What is the ideal rpm range for a 454 mag? I've done a search on 454 mags and all I really got was max rpm. 5200-5400?? What is ideal 4900? Is 4600 to low then?

It's all stock, even the exhaust. I'm thinking about upgrading the exhaust, maybe to the new Dana's. They claim 20-30 hp over stock.

The mag should be good around 5000 rpm. The 7.4 is 4200-4600.

Prop the boat to run 5100rpms with a light load. With a heavy load you'll probably drop 100-200 rpms. 454mags(depending on year) have rev limiters set at 5150.