[olddog]

A friend runs a 385 based 460 bored over in mud runner. The engine was built and dyno showed near 700 hp. He had problems with the engine, and had a different builder work it over. The second builder told him it had way too much cam for his rev limiter set at 6800. He did more port work, changed the cam, and put it back together.

Ran it on the dyno and it was down 100 hp. He was bummed, but out of money. So he put it in his truck. His first run, he was expecting less performance and was totally caught off guard. Hit the rev limiter instantly and thought it was missing for a couple seconds. He has to shift gears immediately.

By the seat of his pants, he is convinced it up at least 150 hp when the dyno says it is down 100 hp. That's about a 250 hp difference from one shop to the other. To me a dyno (other than a huge manufacture with deep pockets at risk) is only useful as a tool for tuning and measuring changes. The absolute numbers are meaningless.