Although this regular installment is named "Horsepower!," you'll likely agree after your read this month's feature that "Torque!" might be applicable this time!

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Block

A 1970 455 block with 2-bolt main caps and ARP main studs serves as the foundation. The cylinders had previously been bored .030-inch. They were taken an additional .005-inch to a total of 4.185 during this rebuild. Custom forged-aluminum pistons from Diamond Pistons fill the cylinders. A forged-steel crankshaft boasting 4.5-inch stroke length and 6.8-inch forged-steel connecting rods from Eagle Specialty Products completes the short block. Total displacement measures 495-ci.

Cylinder Head

Edelbrock's cast-aluminum D-port cylinder heads (number-61595) were treated to a multi-angle valve job and the bowls were blended to increase airflow above the peak values of 260-cfm (intake) and 160-cfm (exhaust) at 0.600-inch lift at 28-inches of pressure that Edelbrock boasts in as-cast form. Combustion chamber volume measures 72 cc. The custom pistons feature a 25 cc dish, which effectively reduces rotating assembly weight and yields a compression ratio of 10.5:1.

Intake Manifold

An Edelbrock Performer RPM intake manifold distributes the combustible cocktail. Its runners were checked to ensure a smooth transition into the cylinder head intake ports. The water crossover was separated from the manifold body for easy removal if required.

Throttle Body

FAST's EZ-EFI provides precise fuel control in all operating conditions. Its ability to continually learn and adjust for optimum performance ensures that the 495 is always operating at peak efficiency regardless of load or RPM. The throttle-body system is capable of delivering 1,000 cfm and is rated for all applications up to 500 cubic-inches, pulling at least 8-inches of vacuum, and producing up to 600 hp. Because the EFI system was previously installed, WAM used its 650-cfm HP-series Holley for the dyno pulls. The additional airflow associated with the EZ-EFI system could increase peak horsepower by as much as 15 units with peak torque remaining much the same.

Valve Cover

A custom-ground Howards Cams hydraulic roller camshaft was designed to maintain good idle and superb low-rpm street manners. The specs are 219/229-degrees duration at 0.050-inch, an 112-degrees lobe separation angle, and an intake centerline degreed at 108.5. Valve lift when combined with Crower's cast-alloy 1.6:1 ratio roller rocker arms is more than 0.550-inch. Manifold vacuum at idle is 19-inches!

Header

Four-tube Dynomax headers feature 1.625-inch primary tubes and 3-inch collectors. A custom-bent 2.5-inch exhaust system featuring a transverse-mounted Flowmaster muffler completes it.

Distributor

A recurved Pontiac HEI provides 22 degrees of mechanical advance by 3,200 rpm. With a base setting of 10 degrees, the 32 degrees of total spark advance perfectly complements the fast-burn combustion chambers of the Edelbrock cylinder heads.