Edelbrock started out using a 350 four-bolt main block from a truck. After a thorough hot tanking, all sharp edges were deburred and the oil return passages (see arrow) in the front and rear of the block were opened up. Once the machining was completed, the block was washed with soap and hot water and allowed to dry completely. A coat of Rust-O-Leum paint was applied to the engine's interior surfaces to aid oil drainback to the pan.

Due to the stress placed on a high rpm engine, Edelbrock used a factory Chevrolet forged steel crank along with factory connecting rods. To enhance engine reliability, the crank forging lines (A) were deburred along with the four-bolt main caps. Factory connecting rods (B) have the side beams ground smooth, polished and shot-peened. The big ends were resized and the small ends are bushed for full floating pins. Holding the rods together are ARP Wave Loc 3/8-inch diameter rod bolts. Torque to 45 ft/lbs.

To ensure an adequate oil supply at higher rpm, the crankshaft oil holes on the rod and main journals were chamfered (A) and all bearing surfaces were micro-polished for an ultra smooth journal surface. Another crank prep tip is to make sure that the journal radii (B) are smooth and have a generous contour.

Circulating the lifeblood of the engine is a TRW high-volume oil pump (part no. 50135) that has had end clearances checked, the housing deburred to prevent cracking (B) along with having the oil pump pickup brazed to the housing cover using low heat to minimize distortion (A). Adding to the engine's reliability is a B&B Performance solid steel oil pump drive rod (C). Edelbrock even goes to the trouble of deburring and chamfering the rear main cap oil cavity (D). Just one of the details that ensures reliability and maximum power output.

Making the requisite 9.5:1 compression is done using TRW Powerforged pistons (#L2417 + .030-inch) with a flat top and a single trough valve relief that has been deburred. Holding the full-floating wrist pin are double Tru-Arc retaining clips (see arrow). Sealing the piston to the cylinder is done via Speed-Pro rings.

To help attain 420 horsepower, the valves are actuated by the Edelbrock Performer RPM camshaft and matching hydraulic lifters. Cam duration specs at 0.050-inch tappet lift are 234 degrees on the intake and 244 degrees on the exhaust. Valve lift on the intake is .488-inch and exhaust lift is .510-inch.

To be certain of maximum timing accuracy with the least amount of play. Edelbrock used their Performer-Link True-Rolling Timing Chain set #7800. For maximum reliability, the gears are chamfered along with having the oil slots (see arrow) in the camshaft gear (where it meets the block) widened for more oil and less wear. Connecting the gears is a double row roller link timing chain that helps reduce friction and chain stretch.

Contributing to the awesome power of the 355 cid small-block Chevy is the Edelbrock Performer RPM aluminum heads. Valve sizes are 2.02-inch intake and 1.60-inch on the exhaust. Contributing to the strength of the Performer RPM head is the deck thickness of .562-inch (see arrow). These heads are available with either straight or angled spark plugs.

Edelbrock offers cylinder heads complete with: bronze valve guides; stainless steel valves; single valve springs with dampeners; steel retainers; and 7-degree, heat treated and machined locks set-up for most street hydraulic and mechanical lifter cams. Other features include Heli-Coiled exhaust bolt holes and spot-faced head bolt holes.

For the breathing necessary to make 420 horses, Edelbrock used their dual plane Performer RPM intake manifold in conjunction with their Performer Series 750 cfm, manual choke carb. To gain that last bit of power and to balance heat dissipation between cylinder banks, an Edelbrock Victor Series aluminum water pump was used. Another item to note is that the Performer RPM aluminum cylinder heads have the accessory bolt holes drilled and tapped to fit all applications.