My brother has a a 23 foot Caravelle with a 350 Mag and a bravo one drive with a 1.50 drive. Im in New Mexico and the lakes here are any where from 4400 feet to 7000 feet. the boat is brand new and came with that drive from another state. He is only getting about 3700 RPMs at wide open throtle.The dealer he bought it from told him he need ed to change out the gears in the drive other wise it could cause severe damage. Im thinking just changeing the prop he has a 21P 3 blade thought he should try a 19P any advise would be great
Thanks Vince

Can't answer the question but if you find you need a 1.65 Bravo upper I have one I'll work a swap with you for.

Russ C.

I think its going to need more than a 2" pitch change. Probably 2" and the gear change or try a 17" prop.

A procharger will solve the problem

Try a smaller prop and if that gives you positive results, you can change the gears if you choose.. 17" prop isnt really considered Hi Perf...
The dealer is probably concerned about the motor being lugged down so hard.. That much load will cause detonation..etc.. and is hard on everything..

and yes that Procharger idea is a good one!