The Small-Block's Range

The small-block Chevy has powered everything from farm trucks that rarely exceed 30 mph to production-bodied land-speed record holders past 300 mph. That range is the point. The same basic architecture adapts to nearly any objective, and this test demonstrates exactly how far a recycled 350 can go with the right sequence of upgrades.

The goal was straightforward: starting from a stock baseline, add 100, 200, and then 300 horsepower in three distinct phases. Each phase represents a different level of commitment, from mild street performance to a dedicated strip combination.

The Baseline: A Wrecking-Yard 350

The starting point was an L65 350 pulled from a half-ton truck at the local wrecking yard, as basic as small-blocks come, right down to the two-barrel Rochester carburetor. Before testing, the short-block was freshened: bored 0.030-over, fitted with forged rods, JE flat-top pistons with valve reliefs, and Total Seal rings. The stock crank was polished and retained. The 882 heads received a valve job, and new bearings, Fel-Pro head gaskets, and ARP head bolts were installed throughout.

The stock cam was retained with new lifters, and a Sean Murphy two-barrel carb (supplied by Westech Performance) replaced the original Rochester. On the dyno with headers and an MSD distributor, this stone-stock two-barrel 355 produced 246 hp at 4,500 rpm and 364 lb-ft of torque at 3,000 rpm.

01. Making power from a recycled 350 Chevy starts with a solid foundation.

02. After removal from the wrecking yard, the block was bored 0.030-over, honed, and decked in preparation for assembly.

03. The stock cast crank was in good shape, needing only a polish before balancing. It was combined with forged rods and JE flat-top pistons prior to assembly.

04. The 882 iron heads were cleaned and given a fresh valve job for the baseline. The press-in rocker studs were drilled and tapped to prevent pulling under load.

05. With the stock cam and two-barrel Rochester, the 350 produced 246 hp and 364 lb-ft of torque. Stock exhaust manifolds were replaced with Hooker headers.

Phase 1: The First 100 Horsepower

The first 100 hp is the most accessible gain because every component on the stock two-barrel engine is a restriction. Replacing the Rochester with a Q-Jet and intake alone accounts for 25-30 hp. Add a mild cam and head upgrade, and the numbers climb quickly.

For this phase, the 882 heads were replaced with a set of as-cast RHS Pro Action aluminum heads featuring 180cc intake ports. The cam moved to a Comp High Energy 252H: 0.425-inch lift, 206 degrees of duration at 0.050, and 110-degree LSA. Topping the combination was a Speedmaster dual-plane intake and Holley 650 HP carburetor.

Result: 347 hp at 5,400 rpm and 399 lb-ft of torque at 3,700 rpm. Peak power and torque both shifted higher in the rpm range compared to the two-barrel configuration, a trend that continued with each successive phase.

06. Off came the stock heads, cam, and intake to make room for the RHS Pro Action heads.

07. The as-cast aluminum RHS heads featured 180cc intake ports, flowing considerably better than the stock 882 iron heads.

08. Exhaust flow is a critical factor in power production, and the RHS heads offered significantly more exhaust flow than the 882s.

09. Static compression increased with the drop in chamber size from 72 cc (882 heads) to 64 cc. The RHS heads also featured a 2.02/1.60 stainless steel valve package.

10. The stock cam was replaced with a Comp High Energy 252H: 0.425-inch lift, 206 degrees of duration at 0.050, and 110-degree LSA.

11. The cast-iron two-barrel setup was replaced with a Holley 750 HP carb and Speedmaster dual-plane intake. Power output moved from 246 hp and 364 lb-ft to 347 hp and 399 lb-ft.

Phase 2: Adding 200 Horsepower

Each successive jump in power demands more from the combination. The Phase 1 components came off, and the 355 received a complete new top-end package built around AFR 195 Eliminator heads. These CNC-ported heads featured 65cc chambers, a 2.05/1.60 valve package, and airflow capacity to support over 550 hp.

The cam stepped up to a Comp Cams XR276HR hydraulic roller: 0.502/0.510-inch lift split, 224/230-degree duration split, and 110-degree LSA. Comp also supplied the lifters, pushrods, and stainless roller rockers. The same Speedmaster dual-plane intake carried over, now paired with a Holley 750 HP carburetor.

Result: 449 hp at 5,900 rpm and 446 lb-ft of torque at 4,600 rpm.

12. The AFR 195 heads were CNC-ported even in Eliminator trim, capable of supporting over 550 hp.

13. The 64cc chambers were selected for this test. The AFR 195s featured a lightweight 8mm-stem 2.05/1.60 valve package.

14. The Comp XR276HR hydraulic roller cam offered a 0.502/0.510-inch lift split, 224/230-degree duration split, and 110-degree LSA.

15. The Comp 1.5-ratio roller rockers carried over from Phase 1. Titanium retainers and ARP hardware secured the AFR heads.

16. On the dyno with a Holley 750 HP carb and Speedmaster dual-plane intake, the 355 produced 449 hp at 5,900 rpm and 446 lb-ft at 4,600 rpm.

Phase 3: The Full 300-Horsepower Gain

The final phase pushed the 355 to 543 hp, nearly 300 over baseline. This combination was oriented toward the strip end of a street/strip build, with reduced street driveability as the trade-off.

The cam moved to a Comp 300BR-16 solid roller: 0.630-inch lift, 264/270-degree duration split, and a tight 106-degree LSA. This profile demanded heads that could match its airflow requirements. The answer was a set of as-cast Brodix Dragon Slayer 225 heads, flowing over 300 cfm with output exceeding 300 cfm even at 0.600-inch lift, a direct match for the roller cam's operating range. The chambers were milled from 68 cc to 65 cc to maintain static compression.

A single-plane Power Plus intake replaced the dual-plane, topped with a Holley 950 HP carburetor and fed spark by an MSD billet distributor.

Result: 543 hp at 6,900 rpm and 463 lb-ft of torque at 5,300 rpm.

17. The Comp solid roller featured 0.630-inch lift with a 264/270-degree duration split and 106-degree LSA, necessary for extracting this level of power from 355 cubic inches.

18. The JE forged pistons featured sufficient valve reliefs for the solid roller cam specs.

19. The Brodix Dragon Slayer heads flowed over 300 cfm, exceeding that mark even at 0.600-inch lift, making them well-suited to the 0.630-lift roller cam.

20. The CNC combustion chambers were milled from 68 cc to 65 cc. The heads were assembled with a 2.08/1.60 valve package.

21. Exhaust flow numbers were equally strong, reaching 210 cfm at 0.700-inch lift.

22. A single-plane high-rise intake matched the high-rpm orientation of the cam and heads. The stainless rockers were replaced with lighter Comp Cams Gold aluminum units.

23. A Holley 950 HP carburetor provided adequate fuel and airflow for the final combination.

24. An MSD billet distributor and wires provided spark energy for the full 543 hp combination.

What the Numbers Show

From 246 hp to 543 hp, each phase illustrates how deliberate component matching drives results. The first 100 hp came from removing the most obvious restrictions. The second 100 hp required better-flowing heads and a more aggressive cam profile. The final 100 hp demanded a purpose-built combination where every component was selected to work at the top of the rpm range.

The Speedmaster dual-plane intake served the first two phases well, delivering the broad torque curve that street-oriented builds rely on. As the combination grew more aggressive, the shift to a single-plane intake matched the high-rpm demands of the solid roller cam and high-flow heads. That progression, from accessible street power to dedicated strip performance, is the range a well-planned 350 build can cover.