Can I swap a 1995 4.3L Alpha 1 Gen II lower unit with 1988 3.7L Alpha I lower unit

rodgeml1

Petty Officer 2nd Class
Joined
Apr 4, 2012
Messages
120
I crunched my lower unit :mad: and it's obviously going to be a pretty penny to have it fixed. I found a 1988 3.7L Alpha I lower drive assembly for sale online and was curious if I could swap one for the other. From what I can tell from looking online, the gear ratio for the 3.7L drive is 1.84, and the ratio for the 4.3L is 1.81. Any advice y'all can provide would be greatly appreciated. Thanks!
 

Bt Doctur

Supreme Mariner
Joined
Aug 29, 2004
Messages
19,093
Re: Can I swap a 1995 4.3L Alpha 1 Gen II lower unit with 1988 3.7L Alpha I lower uni

you cannot swap it, you need a GEN II lower with the correct ratio for your GEN II
 

Bondo

Moderator
Staff member
Joined
Apr 17, 2002
Messages
70,468
Re: Can I swap a 1995 4.3L Alpha 1 Gen II lower unit with 1988 3.7L Alpha I lower uni

I crunched my lower unit :mad: and it's obviously going to be a pretty penny to have it fixed. I found a 1988 3.7L Alpha I lower drive assembly for sale online and was curious if I could swap one for the other. From what I can tell from looking online, the gear ratio for the 3.7L drive is 1.84, and the ratio for the 4.3L is 1.81. Any advice y'all can provide would be greatly appreciated. Thanks!

Ayuh,.... Welcome Aboard,....

You can replace it with a brand new SEI for under $700....
 
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