alpha lower unit compatibility question

G

gholems

Seaman Apprentice
Joined
Jun 26, 2007
Messages
34
Hello,

I have a question about a mercruiser 4.3 L. I need to replace the alpha 1 lower end ( which I think the upper is a 1.84 rotation). I have been offerd a lower end to a 3.0 l mercruiser. Would that be acceptable?

Regards
 
Last edited:
M

mylesm260

Chief Petty Officer
Joined
Sep 13, 2007
Messages
444
Re: mercruiser 3.0 / 4.3

Re: mercruiser 3.0 / 4.3

Short answer: probably.

The gear ratio differences are in the upper unit.

One thing to make sure is that they are of the same generation

There's Pre-MR, MR, Gen 1 and Gen 2, I believe.

It may even be posible to adapt one from a different generation aswell, I know there are only slight differences between them.

I'm sure the experts like don will jump in here and tell you for sure one way or another. In the mean time, try and get the serial numbers of both drives and post them.

And maybe edit your post and change your subject line to be a little more specific. Like "alpha lower unit compatibility question" or something like that
 
Bondo

Bondo

Moderator
Staff member
Joined
Apr 17, 2002
Messages
70,524
Re: mercruiser 3.0 / 4.3

Re: mercruiser 3.0 / 4.3

Ayuh,...

As noted above,...
The Lowers can be Swapped up to, but Not including the Gen.IIs...

Gear Ratios are changed in the Uppers...
 
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