motor swap

MR nova @#25

Petty Officer 2nd Class
Thread starter
Joined
Dec 7, 2011
Messages
150
Will a 1991 Merc 5.7 bolt into a 1990 Merc 4.3 bell housing?
 

Bt Doctur

Supreme Mariner
Joined
Aug 29, 2004
Messages
19,557
It should but the front motor mounts are in the wrong location
 

Scott06

Fleet Admiral
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Apr 20, 2014
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He means don’t send him a question in a private message it’s part of his auto signature not a response to your message
 

Scott Danforth

Grumpy Vintage Moderator still playing with boats
Staff member
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Jul 23, 2011
Messages
53,266
the GM marine motors us the "Chevrolet" bolt pattern. the pattern is the same for the 2.5 (153 cubic inch 4-banger), 3.0 (181 cubic 4-banger)inch), 3.7 (224 cubic in 4-banger), 4.1 (250 cubic inch 6-banger), 4.6 (292 cubic inch 6-banger), 3.8 (229 cubic inch V6), 4.3 (252 cubic inch V6), all SBC V8's and all BBC V8's as well as the Duramax diesels.

so yes, while you can bolt an SBC where the 4.3 V6 was, the drive ratio is different along with the mount locations.
 
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