Best Selling Engine Combos From Top Engine Builders - Proven V-8 Power Trends

This 370-inch combo made just... 

   

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This 370-inch combo made just over 480 hp with 10.5:1 compression.

AMC 360
The AMC 360 is the most common AMC engine in the wrecking yard, so it would seem that it would also be the engine that is the most common build. Not so. Barry Allen from Barry Allen Race Engines tells us that the 401 is king because the 360 is weaker around the main web castings and the stock parts are cast instead of forged. Because of that, only a few 360s are put together for Jeeps and AMC passenger cars in the course of a year. Of those engines, the 450hp version is the most popular.

To get there, Allen uses the stock cylinder-head casting No. 090 or No. 993 from '72-'73 engines because they are already machined for screw-in studs from the factory and have 58cc combustion chambers. For about $800 a set, Allen ports the heads so they flow 270-283 cfm at 0.500 lift, and adds a performance valve job. He uses the stock crankshaft and a set of custom-made stock-length forged rods with ARP cap screws. The pistons are custom-forged flat-tops or dishes, depending on the desired compression ratio. The standard is 10.5:1 for pump-gas engines. The popular camshaft is a Comp Cams hydraulic flat-tappet single-pattern grind with 0.542 lift and 240 degrees of duration ground on a 110-lobe center. It makes 14-15 inches of vacuum and likes a big stall converter.

Allen can modify the stock oil pan to hold an extra quart if you prefer, or you can buy a larger pan from Milodon. If the engine is going to spin above 7,000 rpm, he recommends using -6 AN line that feeds the No. 4 and 5 crankshaft bearings directly from the main oil galley. Allen rebuilds the front timing-chain cover with an oil-pump kit from Melling. Good oil pressure is 20-30 pounds at idle and 60-75 pounds above 6,000 rpm.

Barry Allen Race Engines
Glen Daniel, WV
304/934-6865

The next step above the 420ci... 

   

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The next step above the 420ci engine involves some crazy cash and the Indy block.

AMC 401/420
The highest-volume and most common AMC build is the 420 stroker. It uses a 401 block that had been bored to 4.195 and a stock forged 401 crank that has the rod journal turned down to 2.100 for a 3.800 stroke. The rod journal is then widened to 1.900 for a 6-inch forged Eagle I- or H-beam rod with a floating 0.0927-inch wristpin. The pistons are custom Diamond Racing or Venolia that yield anywhere from 10.0-13.0:1 compression, depending on the application.

Most guys are using the No. 291 iron-head casting from '70-'71 with a 50cc chamber or the No. 090/993 casting from '71-'73 rebuilt and ported to flow above 280 cfm at 0.500 lift. The street version with 10.5:1 compression, a Holley 750HP carb, a Torker intake, and a solid-roller cam with 0.640 lift and 251/260 duration at 0.050 makes about 500-550 hp. There also is a more brutal version that has a 4.250 bore and 3.800 stroke and a 13.5:1 compression ratio. With a custom Comp Cams solid roller with 0.747/0.763 lift and 278/288 duration at 0.050, it makes in the neighborhood of 700-725 that everyone agrees is nearing the limit of the stock block. The next step is a 4.250-bore Indy block with a custom 4.150-stroke Moldex crank for 450-plus inches.

Barry Allen Race Engines
Glen Daniel, WV
304/934-6865

If you are a A-body guy, this... 

   

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If you are a A-body guy, this is the package for you.

Small-Block Mopar 408 CI
Even though the big-block outsells the small-block 10 to 1 these days, we'd be remiss if we didn't find out what small-block guys were building. We asked Mike Ware at Muscle Motors and the simple answer is the 408. Using the original LA 360 ('67-'85) block bored to 4.030 and an Eagle 4.00-inch steel crank, a 10.0:1 compression stroker can make an easy 500 hp and 525 lb-ft of torque. The stock iron block requires only a small notch at the bottom of the cylinder to clear the connecting-rod cap screw.

The stock rods are replaced with a steel H-beam that is 6.123 inches and an off-the-shelf piston from KB or Diamond Racing is used with either a flat-top or dish, depending on the desired compression ratio. Ware also tells us that a hydraulic flat-tappet cam is a cost-effective way to keep prices down and he offers a single-shaft rocker system that works with Edelbrock RPM heads. This is topped with an Edelbrock Performer RPM intake manifold and a Quick Fuel 850 carb. The Mopar A-Body is the target for these engines, so you can also source an oil pan and headers from Muscle Motors and TTI.

Muscle Motors
Lansing, MI
888/482-4900
musclemotorsracing.com