Well, I've got my motor back in the boat. Set the timing and ran in the cam. All this was done with 20w50 Valvoline oil. Now I am wondering, is this heavy weight oil really necessary on a pleasure jet boat? I'm not going to be out racing WOT. Yes, I might jump on it once in a while for very short spurts but, wouldn't something like 10w40 or even 10w30 work just fine? This is a 460 BBF that's .30 over and nothing more than a mid-grade gas motor.