Steve Morris doesn’t typically mess with small-block 355s anymore. In fact, by his own admission, it had been nearly two decades since the last one rolled into his shop. But when longtime supporter Jeff Maisie brought his self-built 355 SBC to the Morris dyno, things got interesting fast.

A Familiar Foundation With Fresh Parts

The engine is built on a stock 010 four-bolt main block and bored to 355 cubic inches. Jeff assembled the engine himself, using Brodix IK 200 heads, a Callies Compstar crank, Compstar rods, and a solid roller valvetrain with Morel lifters. Compression sits at a healthy 12:1, and the camshaft profile is exactly what you’d expect from a classic bracket-style build, one that would feel right at home in the early 2000s.

Steve and his crew handled the machine work on the block, and the plan for the dyno session was simple: dial in the tune, read the plugs, and squeeze every bit of performance out of the setup.

Dialing In The Power

Despite early hiccups from a flaky O2 sensor and plug readings that didn’t quite match the data, the team made quick progress. Richening the jetting and swapping to NGK plugs made it easier to read combustion and confirm that the engine was safe. Over several dyno pulls, they tested different timing values, fuel levels, and even intake spacers. The result? A best pull of 603 horsepower and 500 lb-ft of torque at the crank from this 355 SBC.

Even more impressive was how flat and consistent the power curve became as tuning was refined. Morris noted that the old-school engine took timing well, eventually settling in at 37 degrees total. For a stock block SBC with off-the-shelf parts, that’s serious output.

Classic Hardware, Proven Process

This wasn’t just about making power. Steve used the session to teach viewers how to read spark plugs properly, confirm jetting changes, and avoid relying solely on wideband readings. Instead, the dyno session was a hands-on demonstration of traditional tuning methods, updated with a modern approach to diagnostics and analysis.

It’s a reminder that even in a world full of LS swaps and EFI conversions, there’s still something special about a well-built small-block Chevy on a carburetor. Especially when it makes 600 horsepower and sounds every bit as mean as it looks.