This is the ultimate in stock class clone horsepower. Culley Racing Engines has invested heavily in research, development, and precision machining to deliver unmatched performance and consistency.

At the heart of this build is our blueprinted cylinder head and carburetor package, engineered for maximum flow and power while maintaining full rule compliance. We believe in pushing the limits of the rulebook — walking right up to the line, but never crossing it.

Every engine is painstakingly assembled, inspected, and verified for precision. Nothing leaves our shop unless it meets our exacting performance standards.

This top-tier package comes fully equipped with all linkages, a sleeved header and muffler assembly, chain guard, and all necessary hardware.

We don’t offer “base” models or shortcuts — only top-level builds worthy of our name.

Built for Serious Racers. Engineered for Results.

Starting with the Tillotson Block, each engine is expertly machined to accept the same high-performance internals used in our Pro Open racing builds.

The Cast head assembly is fully modified featuring 32mm intake and 25mm exhaust stainless valves, dual valve springs, and titanium retainers for maximum durability and high-RPM stability.

The compression ratio is carefully calculated and optimized through precision machining, while roller rockers ensure smooth, efficient valve operation.

Inside, every component is performance-driven — a polished and knife-edged crankshaft, billet connecting rod, forged piston, billet crankcase cover, billet Cam, and billet flywheel all come standard.

Choose from Tillotson, Blossom, or Lectron carburetors, paired with a matched header and muffler assembly for ideal airflow and throttle response.

Delivering 30+ horsepower, the 212cc Cast Head Stage 2/3 Modified engine sets a new standard for limited displacement performance.

Starting with the Tillotson Block, each case is expertly machined to accept the high-performance internals used in our top-tier racing builds. 

The head assembly comes in fully modified Cast or Billet options, featuring 32mm intake and 25mm exhaust stainless valves, dual valve springs, and titanium retainers for maximum durability and RPM stability.

 Compression ratio is calculated and optimized through precision machining, while Billet Roller Rockers ensure smooth, efficient valve operation. Inside, you’ll find a polished and knife-edged crankshaft, billet connecting rod, forged piston, billet crankcase cover, billet cam, and a billet flywheel — all standard equipment. Choose from Tillotson, Blossom, or Lectron carburetors, paired with a matched header and muffler assembly for ideal airflow and throttle response. Delivering 35+ horsepower, the Pro Open Small Block isn’t for the faint of heart. With 72mm and 76mm bore options available, this engine defines pure performance. 

Every block is prepared for the high-performance internals we use. The cylinder head is fully modified and equipped with 42mm intake and 32mm exhaust stainless valves, dual valve springs, and titanium retainers. A Billet Roller Rocker system and HD Push Rods complete the top end for maximum stability and efficiency.

Compression ratio is carefully calculated and every component is machined to optimize performance across the entire RPM range. Inside, a Polished, Knife edged, and Balanced crankshaft, billet camshaft. billet connecting rod, forged piston, billet crankcase cover, and billet flywheel are standard equipment — no compromises.

Fuel delivery comes from your choice of Tillotson, Blossom, or Lectron carburetors, tuned precisely for throttle response and top-end power. Each engine is finished with a  Header and Muffler assembly engineered for ideal flow characteristics.

With over 50 horsepower on tap, it’s a beast that demands skill, confidence, and grip to harness. The bore and stroke combination displaces up to 510cc, representing the pinnacle of craftsmanship and performance in the world of racing engines.