[Gonein60]

I have a 392 Ford crate engine with Z heads rated at 475 hp. I used to have a Speed Demon carb but could never get it dialed in so I switched to a Holley 750 and went to the dyno today. With the Demon I was pulling 355hp / 362 torque at the rear but with the Holley I am only pulling 334 hp/ 361. First I can't figure out why I can't pull more than that regardless of the carb as the engine is rated higher (understanding that rwhp is less than at the flywheel rating). I've done all the obvious - timing is good based on what other posters have said (13 idle/34 at 3,000 rpm), air/fuel is 13, everything seems to be working fine. Any ideas what I am missing? Thanks for your comments.