Alpha's behind built small blocks is still not good. I believe it would be easier and less expensive to just keep the big blocks and put bravos on it.
Also, I see a 32' Pachanga with big blocks and alpha drives running around every summer with minimal issues. They can work just not optimal combination.

right, and I would have a lot more boat that way. Thanks for the advice.

got the interior out and the motors out and now and going to start poking around to see if it is dry and what it might need.

My bad. Sorry. Putting much over 400 HP through an Alpha drive just doesn't end well though, so built small blocks might still be problematic as has already been stated. It's not that an Alpha can't live behind a big block or bigger power. The heavier the boat and / or the throttle hand of the driver though, the shorter the life span. I know of one 1987 22' Sea Ray Pachanga right down the lake from me who's still running his original / never rebuilt Alpha behind the 454. To say that he's gentle on it would be an understatement.