They started changing from the 1 drive to the alpha 1 in 1984/1985 time
frame. It's hard to say what you have without splitting the gear cases. The
non alpha drives had a pin sticking out of the top of the vertical
driveshaft.
JIMinFL
"burgs" <burgs.RemoveThis@bigpond.com> wrote in message
news:ig89e.16888$5F3.15782@news-server.bigpond.net.au...
>I have a leg off the back of a mercruiser 470 motor and the only serial
> number I have been able to find (so far) is 5931945 with a large "4" about
> an inch to the right and up about an inch higher than the serial number
> off
> the drive unit. This number does not seem to come up on Alpha one serial
> numbers that I can find, and a manual lists it as a 470R sterndrive. I am
> now toatlly confused between Alpha one, 470 R and model 1 drives Is this
> the same as an alpha one drive? The reason I ask is because I have the
> opportunity to replace my 470 motor with a motor set up for an Alpha one
> drive but now I'm not sure that I have an Alpha one. The drive seems to
> meet
> the description for an early of model 1 alpha drive, but now I just don't
> know!!
>
> Where would I find other nos. on either the lower gearbox unit or maybe
> gimal housing to check out this unit? The Bell housing unit seems to look
> like the diagrams for the later model 1 due to the round shaped rubber
> ring.
>
> Any help would be appreciated.
>
> KenW
>
><!-- ~MESSAGE_AFTER~ -->
>> Stay informed about: trying to identify sterndrive leg from serial no. on drive..