[Skip Fix]

OK guys something I have brought up in previous discussions but no one has ever addressed or refuted- the factory did the apples to apples for us in 71-74 with 455s!

They had D port 455s and HO/SD 455s. The D ports averaged around 150ish ccs the round ports close to 180ish. They were similar compression,similar cams(unlike the RAIV 400s vs D port 400s) and iron vs iron. The round ports flowed more air(tested too many stock ones and D ports) and the increased (almost 30cc) port size did NOT turn them into high rpm race motors. They made more hp and had similar torque curves,look at the factory numbers. So how can that be possible if adding 30cc makes the motor a non streetable pig with no velocity? What's the answer guys-look at the factory specs. Airflow over loss of velocity wins out here too.

How about you fairly stock HO drivers is it a high rpm race motor with those giant heads? It's go no bottom end right??

Yea John those 4.10s make you a race car.But I do agree they are a pain on the freeway,why I'm looking at the 3.42s again.