What about a motor that is not completely stripped to bare aluminum all over? If I use the PPG cleaner & then conditioner and then chromate primer and Awl Grip 2000 will it hold up on a 50mph boat?

The cleaner and conditioner is for bare aluminum. So if you have bare spots use it there. If it's not bare, skip that step; sand as normal and then use Acryliclean before the primer. Yes, it will stand up pretty well to 50 MPH.

Quicksilver Phantom Black is great for drives, but if its stripped down like you say, follow what these guys say and do the works. I shoot only PPG as well, no doubt it will last for many years to come!

thinking of doing mine this year, thanks for asking the question.... send some pics of the finished product.