4.0 in pre 87 jeep XJ

[jeepguy77]

Can you bolt up a 4.0 to a trans that originally had the 2.9 v6 hooked to it or are the bolt patterns different?

[tufcj]

Bolt patterns are different. The 2.8 was a GM built v-6. The firewall is also different between the V-6 and I-6 models. Jeep deepened the center to fit the I-6 in.

You can get a 3.4 crate motor from GM that is a lot peppier than the 2.8 from what I'm told, and it is a bolt in.

Bob
tufcj

[jeepguy77]

Ok thanks Im asking for a friend who has one and wants to get rid of the powerless v6 and if it was possible I figured the I6 would have been the best swap

[ironman_gq]

I think if it was a 90* engine than any 90* GM engine would probably bolt in

[tufcj]

Nope. They used the gutless 2.8, which is a 60* v-6. The 3.8 and 4.3 were the 90* v-6s, which were just a V-8 with 2 cylinders lopped off, and shared the V-8 bolt pattern.

Bob

[jeepguy77]

v8 bolt pattern huh that gives me an idea :mrgreen: :lo1l:

[mrtazwrench]

v8 bolt pattern huh that gives me an idea :mrgreen: :lo1l:

You have the 60 deg pattern, not the V8 pattern.

[jeepguy77]

oh well at least its not my jeep its afriend of mines, my jeep is already powered by a v8