[Gonein60]

Thanks guys - yes, same dyno similar temperature and not sure about the humidity. Per my note I did switch out carbs to a Holley but both the Demon and the Holley are 750's so I wasn't expecting much change other than an easier tune. The Holley has vacuum secondary. Any thoughts on going to a manual secondary with maybe an 800 or 850 double pumper? The specs suggest that 750 is enough but I feel like I am leaving horsepower on the table. I have read a number of posts here and most of the 392's are pulling around 400 rwhp. I'm baffled. Thanks again for any suggestions.