I bought this 1986 Regal 195 cuddy. The lower unit went out. Was probably going out when I bought it. Anyway I put a pre alpha on it and I noticed a difference in speed and rpm. Then I got a Alpha one ( Which is what was originally on it ). I've since picked up a project boat that has the Alpha one and he threw in a pre Alpha, serial number on the drive shaft housing is 2903355 which threw investigating is a 1970-1978 drive off a 165 in-line 6 with a 1.65 gear ratio. My original Alpha One is a 1.84 gear ratio. What I am thinking of doing is since the Alpha one replacement I picked up has a broken skag and the older pre alpha is in great shape I'm thinking of using the old one. The Pre alpha I had on before must have been about the same thing and It pushed my rpm up to around 4800 were as my Alpha one, before it went all the way out, pushed it about 4600 rpm with not allot of variation on speed, A few mph at most with GPS. And the exact same prop on both drives. If I put the pre alpha on and raised the pitch of my prop from 19 to 21 to get the rpm back down to man. specs would Every thing be good with the setup???? I'm fairly new to I/O's I just want to make sure the gear ratio is in the lower unit not in the drive shaft housing.