bearboy Posted January 11, 2014 Share Posted January 11, 2014 I have a 86 Comanche x with a 4.3 chevy motor and auto tranny. its a 4x4.. if I want to swap to a 350 chevy what will I need to do? thanks Link to comment Share on other sites More sharing options...
Jeep Driver Posted January 11, 2014 Share Posted January 11, 2014 Exhaust, engine mounts, radiator, shorten drive shaft, move x-member. I assume it's carbureted? Link to comment Share on other sites More sharing options...
bearboy Posted January 11, 2014 Author Share Posted January 11, 2014 yes it is carberated Link to comment Share on other sites More sharing options...
nitroxsteve Posted January 11, 2014 Share Posted January 11, 2014 Are you sure its a 4.3 and not a 2.8? I think the 4.3 and 350 use the same motor mounts. A long time ago I was involved in removing a Cutlas v6 (3.8 I think) and installing a v8. We reused the motor mounts and even the exhaust system was the same. The Y pipe attached to the v6 manifolds in the same spot as the v8. It may be easy it all depends on how the 4.3 was installed. Post some pictures I would like to see it. Link to comment Share on other sites More sharing options...
bearboy Posted January 11, 2014 Author Share Posted January 11, 2014 I'm sure its a 4.3 I have water in my exhaust and not sure if its the head or a cracked block.i love the rig and want to fix it. I guess ill have to open it up and research more. I don't have a good place to work on it. its outside and the weather in Oregon right now is bad. I should mabe just repair or replace my 4.3 Link to comment Share on other sites More sharing options...
Eagle Posted January 11, 2014 Share Posted January 11, 2014 The 4.3 was never offered in the MJ by Jeep, so if you're certain it's a 4.3, it had to have been swapped in by someone. Did you do it, or was the swap done by a previous owner? The 4.3L is basically a 350 V8 with two cylinders chopped off, so it sounds like transitioning to a V8 would be easy. However ... every XJ or MJ I've seen with a small-block Chevy engine in it has had severe overheating issues. For that reason, I would recommend that you stay with a 4.3L because it just might be a little easier to keep cool. Link to comment Share on other sites More sharing options...
Strokermjcomanche Posted January 11, 2014 Share Posted January 11, 2014 Maybe he has the 3.4 swap out of the camaro? Link to comment Share on other sites More sharing options...
yxmj Posted January 12, 2014 Share Posted January 12, 2014 If it has as you say already been converted to a 4.3....any gm small block would be a minimal work bolt in....(obviously you would need V8 collectors for you exhaust.and any required computer controls) if overheating is a concern ......and to give you more space for the V8.....lose the mechanical fan and go with a electric set up......biggest one you can find or a dually.... would be perfect....... Link to comment Share on other sites More sharing options...
bearboy Posted January 12, 2014 Author Share Posted January 12, 2014 thanks for all the help/advice Link to comment Share on other sites More sharing options...
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