Well, I can say that I know that an alpha will live behind a 454....how long depends on you. I had an 87 Scarab Panther that had twin 454s and Alpha drives on it. I did break several, but that was my fault jumping wakes. I broke the counter rotating drive twice (lower unit both times) and broke the standard rotation drive once (snapped the verticle shaft). I never had a problem with the drives during normal driving. If you really plan to do it, drive it like it's made of glass and make sure you put a drive shower on it. I personally would make the change to a bravo since the engine will be out of the boat...plenty of decent deals out there for regular bravo drives and transom assemblies. Keep in mind that on a single engine boat, if you break the drive...YOUR STUCK! I always had the other motor to get me back to the dock when I broke a drive

A good amount of "How it will last" is going to depend on the current condition of the Alpha, as well as how you drive the boat. If you are a "hard" driver then chances are at some point it's going to break sooner then later. If you can "nurse" the boat and be quick on the stick in the rough stuff then I'd bet you could make it last. However like said earlier if the motor is out you have already done a good part of the work. Do it all the right way the 1ST and last time if possible.

well looks like im gonna wait and do it all at once thanks for all the input guys i appreciate it.

It aint pretty but here is one on ebay...$5 plus shipping with 2 days left. No reserve.

http://www.ebay.com/itm/2001-Bravo-I...e44474&vxp=mtr

this will work for any bravo drive?

Yes. The only difference between a Bravo 1 and a Bravo 3 is the lower unit. The transom assembly will be identical.