422 dyno fail

Sounds like is a nice street engine build. I wouldn’t worry about the low numbers the dyno jet kicked out since it’s at the rear wheels. As noted, the drive train eats up a bunch of power with the transmission being a hungry SOB no matter the model. Power is lost all the way to the wheels. Driveshaft, rear gears, axles and tires. Everything is eating some power.

If that engine itself was on a dyno, I’d add an easy 80-100 hp. The fellas above nailed it I think. The engine build has some good specs to it.