Last time it was on the dyno it made about 740 hp. Major change was from a big flat tappet cam (Comp MM305) to a roller cam. The roller cam had a few degrees less duration than the flat tappet but a ton more lift. Lift went from .650 to .830 on the intake side.

I also changed from a 440-3 intake to a 440-3X and I put a belt drive on the motor as well as a reverse flow water pump.

I doubt the belt drive or water pump made a power difference so I'm guessing it was mostly due to the cam change. I was going to do a -3 vs. -3X intake shoot out but ran out of time. Besides, the dyno operator wasn't too happy because the dyno needle was bouncing off the stops. His dyno torque gauge is only setup for about 700 ft-lbs and we were getting really close to that.

One other change I made was that I leaned out the intermediate circuit on my Holley Ultra HP by 80% from stock. Stock was an 46 jet and I leaned it out to a 20 jet. That is a 80% reduction in area and it seemed to work. The AF ratio leaned out to about 12.5 and stayed that way for the entire pull. With the stock jetting the motor would start the pull at 10:1 and then gradually lean down to 12 or so. I'm sure the carb tuning picked up some power too.