twin blown 350s w/ standard alphas
 

I am taking delivery of a 1988 Sea Ray Pachanga 27 with twin blown roller 350s 425hp to 475hp with STANDARD Alpha drives 25hrs on motors and 25hrs on new drives running 21 4 blade props. Can I run 23s-25s or is this to much stress how long will these drives last with the current props?

Re: twin blown 350s w/ standard alphas
 

23p - 3 blade might not be much of an improvement. I would consider sticking with what you have. The drives were designed with about 270 hp max in mind. Look at the history of Alpha's with 330 hp big blocks. Was not a very good idea. Keep the props in the water, don't pull any full throttle hole shots and the drives could live for some time. Some would consider the combo a time bomb, tho.
Good luck!