Ross Racing Engines' Tony Lombardi cut the valve reliefs using an end mill and his adjustable piston vise.
Build, text and photos by Mike Mavrigian
The Pontiac bigblock build (starting with a 455 block and boring/stroking to 501 CID) is progressing. I apologize for the time delay, but this build has been taking place amidst a slew of other projects. At this point, everything has been clearanced and test fitted, and the crank was just recently balanced. Now it’s time to paint the block and assemble the long block, leaving only the task of measuring for custom pushrod length prior to completion.
I previously ground the block exterior smooth. Now that all clearancing and test fitting has been accomplished, we can finally paint the block. This requires a final-prep of the block exterior, which I’ll get into in this article. I delayed block painting until I was certain that no additional machining was required.
HEAD TO BLOCK DOWELS
The 455 block requires two dowel pins per bank. These are located immediately underneath the top front top and top rear head bolt holes. I installed a set of Pioneer S-1110 dowels, which are also part-numbered for 283-400 Chevy applications. The pins measure 5/16”-diameter x ½”-long. Installed these at half-depth, leaving 0.250” exposed above deck. The blind dowel holes in the Kaufman heads provide about 0.450” of depth. Note: the dowel holes in the block are open to water (don’t ask why, as I don’t have a clue). This shouldn’t pose an issue due to the interference fit of the dowel pins plus the sealing of the head gaskets.
Tony cut both intake and exhaust valve reliefs the same diameter and depth, sizing for the 2.110" intakes. Using his 2.180" cutter, this provided a 0.070" margin. Exhaust pockets were sized the same as the intakes, and at a depth of 0.250" in order to reduce compression to 11.26:1.
After the valve reliefs were cut, I test-assembled again to verify clearances. Shown here is a piston in the as-cut state. Once I was comfy with clearances, I softened the machined edges, chamfering edges back to a radiused/soft roll.
The sharp transition "V" between valves was laid back at a 45-degree angle and blended to eliminate any potential hot spots that would cause detonation.
Even though I check clearances with heads installed (fitted with lightweight checking springs) and dial indicator throughout camshaft rotation, I also did a clay check as a backup check. Granted, we have more clearance than we need mechanically, the added depth of the relief cuts were necessary to drop our compression down to a livable street level.
The cam was degreed both to verify the grind and to determine valve to piston clearance at our selected 4-degree advance timing.
PISTON VALVE RELIEFS
After checking our valve to piston clearance during mockup, we determined that the flat-top pistons needed valve reliefs, both from a standpoint of clearance as well as to reduce pour compression ratio to a livable level for street use. With a cylinder head temporarily installed (and with number 1 and 3 valves removed from the head), I grabbed a spare valve (with 0.340” diameter stem) and cut off the head. I then chucked the cut stem in my lathe and turned the cut end to a centered point to serve as a punch. With the piston at TDC, I inserted the “punch” through each guide, and gently tapped a small dimple into the piston with a plastic hammer. This provided a center-mark for each valve position. Tony Lombardi at Ross Racing Engines fly-cut each piston to create our needed valve reliefs, using the punch marks as a valve-center reference. Since we needed to drop compression a bit anyway, Tony cut all reliefs sizes for the larger 2.110” intake valves, removing a total of 7cc from each piston (creating a positive volume of 7cc). Tony used his 2.180” cutter. This allows a margin of 0.070” clearance between the intake valve heads and the walls of the relief pockets. Each piston was placed in his adjustable piston fixture, tilt-adjusted to accommodate our 14-degree Kaufman heads. Tony cut each pocket to a max depth of 0.250” (during my test-fitting and checking, I determined that I needed at least 0.210” depth cuts for proper valve clearance, but since we knew that compression needed to be reduced anyway, we opted for a generous 0.250”-deep cut. In conjunction with 0.045”-thick head gaskets, this will provide us with a final compression ratio of 11.26:1. After test-fitting the cut pistons, I measured intake valve clearance at 0.440” and exhaust valve clearance at 0.455” (without a head gasket). Adding a 0.045” allowance for the gasket, this gives us a final intake and exhaust clearance of 0.485”/0.500”. I verified intake valve clearance with the crank at 10 degrees ATDC; and exhaust valve clearance at 10 degrees BTDC (the points at which the valves would be closest to the pistons). I double-checked clearance, this time using clay on the piston (allowing the valves and piston to cycle). Granted, this is far more valve-to-piston clearance than needed, but the 0.250”-deep reliefs were primarily done to reduce our compression to a street-livable 11.26:1. In addition, if we ever decide to swap cams for a higher-lift grind, we’ll have room without the need to further modify the pistons. Once I verified valve to piston clearance, I removed the pistons and carefully “softened” the fresh pocket cut edges, starting with a fine-tooth tapered cutting bit, followed by an 80-grit “tootsie roll” abrasive roll on a high-speed die grinder, followed by a 220-grit roll, finished off by hand using a piece of red Scotchbrite pad and a through rinsing. I slightly chamfered the edges back and lightly blended to eliminate all sharp edges that could otherwise promote combustion hot spots. NOTE: Naturally, I could have ordered the pistons with these valve relief cuts directly from JE. However, I wanted to start with flat-tops so that I could perform the exercise of test fitting and determining needed clearance and compression ratio. I look at it as a learning experience.
I opted for MLS (multi-layer steel) head gaskets. When I calculated for compression ratio, I factored in a compressed gasket thickness of 0.045”. For the Pontiac 455 block, and to accommodate our bore diameter of 4.211”, I had two choices in terms of available gasket bore diameter: 4.220” or 4.300”. With a gasket bore diameter of 4.220”, our final compression ratio would be 11.3:1. With a gasket bore diameter of 4.300”, compression ratio would be 11.26:1. It’s a small window of change, so in essence, I flipped a coin and opted for the 4.300” bore diameter gasket to grab 11.26:1 compression. I fully realize that it wouldn’t make much difference, but with today’s fuel, I swayed my decision on the “safer” side.
DETERMINING PUSHROD LENGTH
Once the short block is final-assembled (after block painting) and the heads are installed, we can perform a final measurement for intake and exhaust pushrod lengths. I’ll detail that procedure in the next article, but here I’ll describe what’s involved. Determining pushrod length is a simple deal. First, wipe the valve stem tip clean and paint the stem tip with a magic marker or machinist dye. Rotate the cam until the lifter is on its base circle. Using an adjustable checking pushrod (these are available in a wide range of lengths), install the checking pushrod and the rocker arm. Adjust the 2-piece checking pushrod until you achieve a soft zero rocker arm to valve clearance (you should be able to easily rotate the pushrod by hand). Inspect the rocker arm-to-valve-tip contact area. By rotating the cam from base circle to lobe peak, the rocker arm should be relatively centered on the valve stem tip. Remove the rocker arm and inspect the witness mark on the valve stem tip (where the rocker arm rubbed against the magic marker/dye area). If the witness mark is biased inboard, the pushrod needs to be longer. If the witness mark is biased outboard, you need a shorter pushrod. Basically, you want the rocker arm contact on the valve stem to remain as centered as possible throughout the lift cycle. Adjust the checking pushrod accordingly and re-test. Once the checking pushrod has been adjusted to the proper length, carefully remove it (without disturbing its setting) and measure the checking pushrod’s total length (using a long caliper. For measuring a pushrod in the 8” range, for example, you’ll need a dial or digital caliper that is capable of measuring up to, say, 9” or 10”. Note that some checking pushrods feature reference marks at the mating area (Comp Cams’ Hi-Tech checking pushrods for example). In these cases, the maker’s instructions will indicate that one complete turn will equal 0.050” in length change. For instance, if the checker offers adjustment from 7.8” to 8.8”, in it’s fully shortened condition (mating faces butted together and reference mark aligned), the checker measures 7.8”. One complete turn (360-degree turn) while lengthening the pushrod results in a length of 7.850. Two turns results in a length of 7.900”, etc. This type of checking pushrod allows you to determine needed length without using a long-range caliper, as long as you carefully note how many revolutions you make while adjusting the pushrod. Checking pushrods are available in both ball-ball and ball-cup styles (ball at the lifter end and either ball or cup at the rocker end). Perform this pushrod length check for at least one intake and one exhaust position. Theoretically, if all valves are the same length, all pushrods will likely be the same length. But it’s best to check. If you have the time, you should really check all intake and exhaust positions (all 16), but again, at the very least, check one intake and one exhaust position. In our case, since I knew that our intake and exhaust valve lengths differ, I already knew that we would need one pushrod length for intake and a different length for exhaust. NOTE: When determining pushrod length, the head gasket must be in place (otherwise, you’ll mistakenly calculate for pushrods that would be too short). NOTE: Be aware that a short run of Comp’s Hi-Tech checking pushrods were accidentally mis-labeled and may be 1” shorter than advertised. I bought a 7703-1 and a 7704-1. The 7703 was listed as ranging from 7.8 to 8.8”, and the 7704 was listed as 8.8 to 9.8”. In fact, my 7703 measured 6.8 to 7.8 and my 7704 measured 7.8 to 8.8”. I contacted Comp, and they’re aware of the glitch. I only mention this for those who plan to order these checking pushrods. Regardless of where you buy them, I suggest that you measure to verify length before using. If it’s mis-labeled, Comp will gladly swap out for the length you wanted. Comp’s quality is never an issue, but in this case, it was a matter of simple mis-labeling the last digit of the laser-etched part numbers. I like using the Hi-Tech (simple threaded adjustment with no locknuts to mess with), but I always measure the adjusted pushrod with my digital caliper rather than counting adjustment revolutions.
OUR FINAL COMPRESSION RATIO CHART
BORE…………………………4.211” STROKE……………………...4.500” ROD LENGTH……………….6.700” GASKET BORE……………...4.300” COMPRESSED GASKET……0.045” BLOCK DECK HEIGHT……10.210” TOP RING DOWN………….. 0.220” CHAMBER VOLUME……… 81.5cc DOME VOLUME…………… + 7 cc PISTON TO DECK………….. 0 TOTAL VOLUME…………….1127.15 cc CYLINDER VOLUME………..1027.04 cc CLEARANCE VOLUME…….. 100.1 cc (volume above deck) GASKET VOLUME………….. 10.7 cc TOP RING VOLUME………… 0.9 cc DECK VOLUME……………… 0 PISTON TOP LAND………….. 4.173” (piston land diameter) ½ STROKE……………………. 2.25” PISTON COMP. HEIGHT…….. 1.260” CUBIC INCHES……………….. 501.38 CID
COMPRESSION RATIO………. 11.26:1
The crank was balanced at Medina Mountain Motors in Creston, OH (an engine machine shop that’s a mere ½-mile from my shop). As expected, our set of JE pistons each weighed in between 490.9 and 491.1 g, so we used 491g as our piston weight. The Scat forged rods were also so close in out-of-the-box weight (small ends, big ends and total weights) that no corrections were needed to the rods. All small ends weighed 250.9 to 251.1, so we used 251 g as our small end weight. Big ends all weighed in between 566.9 to 567.1, so we used 567 g as our big end weight. That’s a testimony to the quality and consistency of today’s forgings and machining as exemplified by both JE and Scat.
All pistons were weighed for comparison, with no corrections required (always a pleasure to use JE pistons). In order to create the bobweights, we weighed pistons, piston pins, pin locks, rod bearings, ring packages and rods.
Rods were weighed at the small ends, big ends a finally for total weight. As with the JE pistons, the Scat rods needed no corrections. Both the JE pistons and Scat rods were so closely weight-matched at the factory that no material removal was needed to create uniformly equal mass. This is a far cry from using OE parts that usually require tedious weight matching.
Once bobweight was determined, the bobweights were installed to the crank. Note that each bobweight is installed at 90-degrees to the adjacent bobweight.
The initial spin (with bobweights installed) revealed the need to simply remove 20 grams from the front and rear counterweights.
Medina Mountain Motors' Jody Holtrey using the built-in drill press on his Hines balancer to begin removing weight from the rear counterweight. Jody crept-up on final balance, routinely stopping to spin-check.
Drilling was done at relatively low speed using a carbid drill. The Ohio Crankshaft forging is definitely a piece of very hard material. Once the required 20 grams was removed, Jody lightly chamfered the drilled cavities to eliminate sharp edges.
Ohio Crankshaft definitely did a nice job. The crank was arrow-straight, all dimensions measured exactly on-spec, and required minimal weight correction to accommodate our piston/rod combination.
Ohio Crank also thoughtfully labeled the crank for maximum counterbalance weight (2300 g). If our bobweights had required more than 2300 g, heavy-metal slugs would have been required. Luckily, we only needed to remove 20 grams. This was one of the easiest crank balancing jobs I've ever seen.
After setting up and installing the bobweights, the crank was spun to check initial balance. As it turns out, it only required removal of about 20 grams (at the front and rear counterweights). Ohio Crankshaft’s forged stroker crank was already very close to final balance with our setup. Two shallow reliefs were drilled into the counterweights to bring the crank to within 2 g of balance. A mere 2 g is nothing to be concerned about, since the variable of parasitic oil clinging/releasing during engine operation will more than offset this. Trying to attain “zero” balance on a shop’s balancer is really a waste of time and won’t result in any further advantage. Balancing the crank to within 8 grams is just fine. We lucked out (primarily due to the lightweight JE pistons and pins, and because of Ohio Crankshaft’s expert design work. Whenever you can balance a crankshaft by removing just a bit of material, with no need to add (expensive) heavy metal tungsten slugs, it’s a good day. Ohio Crankshaft laser-etched the maximum counterbalance weight on the face of the front counterweight at 2300 g (indicating that the counterweights were set up to accommodate up to 2300 g…..since our total weight came in at 2188g, we only had to remove weight as opposed to adding weight).
OUR BOBWEIGHT CARD
Piston…………..……..491 g Piston pin………….… 150 g Rings (w/support rail)….62 g Pin locks (4 per piston).. 4 g Rod small end………….251 g Rod big end……………567 g (x 2 = 1134 g) Rod bearings………….. 48 g (x 2 = 96 g) Total………………….2188 g ½ total…………………1094 g (50% factor) Parasitic oil …………..+4g = 1098 g (50% factor) Bobweight…………….1108 g (50.5% factor..overbalance by 0.5%)
WASH BLOCK PRIOR TO PAINT PREP
At this point, all of the machining as well as rough-in exterior-surface grinding/smoothing was done, so it was time to prep the block for final paint. This would involve applying a high-build urethane primer, sanding that primer to a finessed finish, applying a thin “seal-coat” of primer, applying our color basecoat, and finishing with a clearcoat. With the block empty, I washed the entire block using hot water and Dawn dishwashing soap. This included meticulously rifle-brushing all oil passages and all bolt holes. For the cylinders, I used Goodson’s 4.5”-diameter CWB-45 Cylinder Washing Brush. For the cam bearings, I used Goodson’s P/N CBB-200 2”-diameter Cam Bore Washing brush. Once thoroughly rinsed, I blew the block dry with compressed air (including all passages and blond holes). I then immediately lightly oiled the cylinder walls and main saddles to prevent surface rusting.
Goodson offers a wide array of cleaning brushes for every concievable bore diameter. Shown here are 4" and 4.5" diameter cylinder bore brushes.
Here, I'm using a 4.5" diameter cylinder bore brush to wash the block's bores, using hot water and Dawn dishwashing soap. The bristle-count and long handle makes this task easy.
Here, I'm using Goodson's 2" cam bore cleaning brush to wash the cam bores. After the block was thoroughly washed, rinsed and dried, I carefully masked the block in preparation for priming.
I then installed a set of six brass 1 61/64” expansion plugs to the sides of the block’s water holes, from Pioneer’s block plug kit P/N PE-115-B, which includes eight 1 61/64” brass plugs, one 2 1/16” cam bore plug, one 15/16” rear galley plug, 2 9/16” front galley plugs and two 3/8” NPT threaded plugs. I applied a light coat of UltraCopper RTV to the sides of each expansion plug and seated all plugs with an aluminum cup driver to bring the plug edges flush with the block surfaces.
Once we sprayed a coat of heavy-build epoxy primer, we began to sand the primer to eliminate high spots and to obtain a consistent, smooth finish. We started with 220-grit, followed by 320-grit, followed by 400-grit.
Final primer sanding is a tedious job. The 455 block has so many nooks and crannies that you'll wear out your fingertips in short order. Once sanding was done, all masking is removed, the block is thoroughly washed and rinsed again, dried, and then painstakingly re-masked to accept a thinned primer "seal" coat, followed by base color and clear. Once the clear has been applied, we'll wait about three minutes or so, then carefully remove masking to allow clearcoat edges to "soften-blend" to eliminate sharp clearcoat edges. The clear will then be allowed to cure for a couple of days before performing a final wash/rinse prior to final assembly.
Since my objective was to create a smooth and finely-detailed block exterior, once all block water hole expansion plugs were installed (and the RTV allowed to cure overnight), I applied a smear of USC All Metal body filler to the seams around the perimeter of the expansion plugs, in order to obtain a “seamless” plug appearance. After the filler was allowed to cure overnight, I sanded the excess filler down with 80-grit paper, followed by careful sanding with 220 grit. All Metal body filler contains powdered aluminum and withstands high heat applications (good for engine block dressing, and good for prepping any metal component that will be powdercoated, since it withstands oven heat). And yes, in case you’re wondering, sealing the expansion plugs with All Metal would make it tough to remove these plugs in the future, so from a purely service-functional standpoint, this is an idiotic thing to do. However, I don’t plan to re-do this engine from a bare block anytime soon, so in the pursuit of a detailed appearance, I’ll risk it. It’s my call. If the plugs need to be popped out at some later date, I’ll simply deal with it. I just wanted to point out that I didn’t ignore this issue. After blowing the block clean with compressed air, I then carefully masked the block to protect deck surfaces, cylinders, mains, cam bearings, lifter bores, etc. I then applied a coat of heavy-build epoxy primer (4:1 mix with activator) to the exposed block surfaces. This high-build primer serves to fill and hide any minor surface imperfections (sanding scratches, tiny pinholes, etc.). Now comes the tedious part: sanding the primer to create a smooth finish, void of any high or low spots. This is done using 220-grit paper, followed by 320 and 400-grit. This final sanding is mind-numbing and will wear down your fingertips and fingernails. After two days of finish-sanding, the next step will be to remove the masking, performing another careful wash & rinse and re-masking. At that point, we can lay the base color and clearcoat. I plan to use the original 1966-1970 Pontiac light metallic blue color to the block and timing cover (I’ll have my local paint shop custom mix this exact color in a basecoat formula), which will provide a nice touch of brightness (this color features a very fine metallic content for light reflection). Once the block has been colored and cleared, I’ll allow the clear to cure overnight. At that point, I’ll perform a final hot water/soap cleaning and rinse of the entire block. The block will then be moved back into my engine assembly clean room. I’ll wait another few days for the clear to cure further before I begin final assembly. By the way, if you’re wondering about the use of a urethane basecoat/clearcoat system surviving an engine block application, yes, it does work. For example, on a recent build (the Dart-block 427 CID build, where I used a Dart 351W block and bored/stroked to 427), I smoothed the block and painted with basecoat/clearcoat urethane. That engine ran on the dyno for about a dozen pulls (definitely got as hot as it’s every going to), without a single paint problem (no hazing, flaking, lifting, burning, discoloration, etc.). I’ve done about 15 blocks with a baecoat/clearcoat and have never had a problem.
MY PARTS LIST
BLOCK………………………..Original Pontiac 455 (core) CRANKSHAFT……………….Ohio Crankshaft P/N 44554500P 4340 forged, with 4.500” stroke, 455 mains and BBC rod pins CONN. RODS………………….Scat forged 6.700” BBC P/N 2-454-6700-2200 STEEL CENTER MAIN CAPS..Pro-gram Engineering P/N P455C MAIN STUDS…………………ARP P/N 194-5601 HEAD STUDS…………………ARP P/N 190-4305 CYL. HEADS………………….Kaufman Racing aluminum D-port, 81cc CNC CAMSHAFT/LIFTERS………..Comp Cams hyd. roller P/N CL51-433-9 ROCKERS……………………..Harland Sharp alum. rollers, P/N S6001 (1.5:1) PISTONS……………………….JE forged aluminum (custom order) TIMING GEARS……………….Melling Performance P/N 40408 OIL PUMP………………………Melling Performance P/N 10540 TIMING COVER……………….EQ (EngineQuest) P/N TC400N INTAKE VALVES………………Del West titanium (custom order: 2.10” x 5.100”) EXHAUST VALVES……………Ferrea stainless steel P/N F5144 (1.77” x 5.100”) VALVE SPRINGS………………Comp Cams P/N 995-16 (330 lb, triple) RETAINERS…………………….Comp Cams 740-16 (10-deg, steel) VALVE LOCKS EXH…………..Comp Cams 613-16 (10-deg Superlocks) VALVE LOCKS INT……………Manley 13161-8 (10-deg Beadlock) VALVE SEALS…………………Comp Cams, Teflon VALVE SPRING LOCATORS…Comp Cams 4771-16 BALANCER…………………….Fluidampr P/N 650401 (6-5/8”) FLEXPLATE……………………PRW P/N 1845503 INTAKE MANIFOLD…………..Professional Products Hurricane P/N 56031 CARBURETOR…………………Holley P/N 0-82851 (850 cfm) CARB. FEED……………………Earls –8, P/N AT101286ER DISTRIBUTOR…………………MSD Pro Billet P/N 8563 SPARK PLUG WIRES………….MSD P/N 31179 LIFTER VALLEY COVER……..Kaufman Racing GASKET SET …………………...Mahle Victor FS3494J MAIN BEARINGS……………...Mahle Clevite P/N MS667P ROD BEARINGS……………….Mahle Clevite P/N CB743HN CAM BEARINGS……………….Mahle Clevite P/N SH2925 VALVE COVERS……………….PRW aluminum, satin OIL PAN…………………………TBA WATER PUMP………………….Tuff Stuff 1475NA (chrome) or PRW 1445510 ALTERNATOR…………………Tuff Stuff, P/N 7139ABULL (100A, chrome) OIL PAN STUDS……………….ARP 400-1902 INTAKE MANIFOLD BOLTS…ARP 494-2101 ROCKER STUDS……………….ARP 100-7101 CARB STUDS…………………..ARP400-2403 TIMING COVER BOLTS……....ARP 490-1501 FUEL PUMP BOLTS…………...ARP 490-1601 THERMOSTAT BOLTS………..ARP 490-7401 DISTRIBUTOR STUD……….…ARP 490-1701 CAMSHAFT BOLT……………..ARP 190-1001 VALVE COVER STUDS………..ARP 400-7504 FLEXPLATE BOLTS…………....ARP 200-2904 CRANK BALANCER BOLT……ARP 190-2501 HEAD TO BLOCK DOWELS…..Pioneer S-1110 CAMSHAFT NOSE SPACER WASHER….Kaufman Racing (takes the place of the OE eccentric fuel pump re thickness) ENGINE LIFT HOOKS……………Kaufman Racing ASSEMBLY CHEMICALS……….Valco, ARP, Royal Purple .
OUR PROJECT’S SUPPLIER DIRECTORY
ARP, INC. 1863 Eastman Ave. Ventura, CA 93003 800-826-3045 www.arp-bolts.com Birchwood Automotive Group 10205 Wooster Pike Rd. Creston, OH 44217 330-435-6347 www.birchwoodautomotive.com Comp Cams 3406 Democrat Rd. Memphis, TN 38118 800-999-0853 www.compcams.com Del West Engineering 28128 W. Livingston Ave. Valencia, CA 91355 800-990-2779 www.delwestusa.com Earl’s Performance Plumbing Holley Performance Products P.O. Box 10360 Bowling Green, KY 42102 270-782-2900 www.holley.com EQ (Enginequest) 2580 N. Commerce St. North Las Vegas, NV 89030-3876 800-426-8771 www.enginequest.com Ferrea Racing Components 2600 NW 55th Ct., Suite 234 Ft. Lauderdale, FL 33309 888-733-2505 www.ferrea.com Fluidampr-Horschel Motorsports 180 Zoar Valley Rd. Springville, NY 14141 716-592-1000 www.fluidampr.com Goodson Tools & Supplies 156 Galewski Dr. Winona, MN 55987 800-533-8010 www.goodson.com Harland Sharp 19769 Progress Dr. Strongsville, OH 44149 440-238-3260 www.harlandsharp.com Holley Performance Products P.O. Box 10360 Bowling Green, KY 42102 270-782-2900 www.holley.com JE Pistons Inc. 15312 Connector Lane Huntington Beach, CA 92649 714-898-9763 www.jepistons.com Kaufman Racing Equipment 22280 Temple Rd. Glenmont, OH 44628 740-599-5000 www.krepower.com Lista International 106 Lowland St. Holliston, MA 01746 800-722-3020 www.listaintl.com Mahle Clevite 1350 Eisenhower Place Ann Arbor, MI 48108-3282 734-975-4777 www.engineparts.com Mac Tools 505 N. Cleveland Ave. Westerville, OH 43082 800-622-8665 www.mactools.com MSD Ignition 1490 Henry Brennan Dr. El Paso, TX 79936-6805 915-857-5200 www.msdignition.com Ohio Crankshaft 5453 South State Route 49 Greenville, OH 45331 800-333-7113 www.ohiocrank.com Professional Products 12705 S. Van Ness Ave. Hawthorne, CA 90250 800-478-5441 www.professional-products.com Pro-Gram Engineering Corp. P.O. Box 472 Barberton, OH 44203 330-745-1004 www.pro-gram.com PRW (Performance Racing Warehouse) 193 West Orangethorpe Ave. Placentia, CA 92870 714-792-1000 www.performanceracingwarehouse.com Ross Racing Engines 1763 N. Main St. Niles, OH 44446-1277 330-544-4466 www.rossracingengines.com Royal Purple Ltd. One Royal Purple Lane Porter, TX 77365 888-382-6300 www.royalpurple.com Scat Enterprises 1400 Kingsdale Ave. Redondo Beach, CA 90278-3983 310-370-5501 www.scatcrankshafts.com Snap-On Tools 2801 80th St. Kenosha, WI 53143-5699 262-656-5200 www.snapon.com Summit Racing P.O. Box 909 Akron, OH 44398-6177 800-230-3030 www.summitracing.com Trick Flow Specialties 285 West Ave. Tallmadge, OH 44278 888-841-6556 www.trickflow.com Tuff Stuff Performance Accessories 9004 Madison Ave. Cleveland, OH 44102-2715 800-331-6562 www.tuffstuffperformance.com Valco Cincinnati CP, Inc. 411 Circle Freeway Dr. Cincinnati, OH 45246-1284 800-788-3865 www.valco-cp.com