Chevy 2.5 lower unit the same as 4.3.

[bdubs217]

I have a 92 rinker with a 4.3 mercruiser and I hit a log last year and the lower unit is messed up. Bent prob bent shafts and no water up to the motor now. A friend gave me another boat it's an 88 star craft with a Chevy 2.5 4 cylinder and everything in the lower unit looks to be the same so I want to just swap the whole upper and lower units but am not sure if there is any gearing issues or anything else I should be checking. Any help would be appreatiated.

 

[Bondo]

Ayuh,..... The '88 should be an Alpha 1,....

The '92 oughta be a Gen.II,....

They don't interchange, at All,....

 

[thumpar]

Even if the they were the same type drive the ratio would be wrong.

 

[bdubs217]

Both are an alpha 1 generation 1. Would the lower unit atleast be the same? All my damage is in the lower unit. I figured the gear ratio would be different but is the gearing in the upper part?

 

[Bt Doctur]

all the lower units are the same in the MC1,R,MR,Alpha and will straight swap

 

[thumpar]

Are you sure the 92 is a Gen 1? In that year it should be a Gen 2. It could be a left over drive but it is a couple years off.

 

[bdubs217]

From all the pictures and links I have seen mine is an alpha 1 generation 1. It does not have the 4 bolt holding the case together. The drain plug is real low on the unit. And the lower unit has a strait skeg. I had a used lower unit put on a few years ago is there a chance the guy swapped my generation 2 for a generation 1? Is this possible?

 

[Bondo]

Is this possible?

Nope,....

 

[duped]

Serial number, or even better, a picture of your current drive would remove any doubt.