Speedway Motors Racing Engines CT400 IMCA-Sealed 604 Crate Engine

A Speedway Motors Racing Engines CT400, commonly called the "604 crate," an IMCA-sealed 350 cubic inch engine rated at 400 horsepower built around GM's Fast Burn cylinder heads for Modified and Late Model classes.

What's inside

This build starts from the Fast Burn 385 street crate engine platform, then swaps in an 8-quart, dual kick-out circle track oil pan built for racing use, a valve cover breather kit, and a "kool nut" rocker arm design, along with a high-rise, open-plenum Eliminator Vortec intake and roller rockers in aluminum running a 1.5:1 ratio. The bottom end uses a forged 4340 steel crankshaft and hypereutectic pistons, with 23-degree Fast Burn aluminum heads at a 9.72:1 compression ratio and 62cc combustion chambers, on a 4.00 x 3.48-inch bore and stroke with 4-bolt main caps.

What "IMCA sealed" means

The engine is sealed with IMCA-issued bolts and approved for IMCA competition, so confirm your series and track rules accept this specific sealed build before ordering. It ships as a fully assembled long block with black steel breathered valve covers, oil pump, pickup, and 8-quart pan, spark plugs, an 8-inch harmonic balancer, and front timing cover included, and this engine carries no warranty.

Common questions

What horsepower and rpm is it rated at? 400 hp at 5,500 rpm, with 400 ft-lbs of torque at 4,500 rpm.

Is this street legal? No, the emissions notice on this listing restricts it to racing (competition) vehicles not registered for public roads.