B2 Engine swap

Reply Subscribe

Thread Tools

Search this Thread

May 30, 2010 | 10:04 PM

fran40jomo

Thread Starter

New User

Joined: May 2010

Posts: 3

Likes: 0

B2 Engine swap

Has anyone tried putting the 4.0 or 3.0 v6 into an 87 b2. We are tired of the 2.9 problems. Any special things to know or will it bolt up to the auto tranny we have now?

May 31, 2010 | 10:00 PM

mrshorty

Postmaster

Joined: Dec 2001

Posts: 3,742

Likes: 2

From: UT

4.0 is in the same family as the 2.9 and is reportedly a straightforward swap. If you put something like "4.0 into bronco II" into this site's search engine you'll find many people who have talked about it and some who have done it.

I expect someone somewhere has tried a 3.0 swap, but it would be a bit more involved, and you would need to figure out how to attach the transmission and everything.

Jun 1, 2010 | 12:02 AM

rebocardo

Post Fiend

Joined: Jun 2002

Posts: 13,873

Likes: 3

From: Atlanta GA

If I didn't have to met emissions I would go with a 2.8L, holley, and duraspark conversion.

A4LD behind your 2.9L is not likely to hold up to the 4.0L for long.

Jun 1, 2010 | 04:55 PM

Eddiec1564

Cargo Master

Joined: Mar 2007

Posts: 2,935

Likes: 34

From: Arcadia, Fla

Get a 4.0L engine/a4ld from a 91 to 94 Explorer. The engine/tranny will directly bolt in. Wireing may have to be modifed where the engine harness meets the firewall.

Jun 14, 2010 | 02:47 PM

Skiboarder

New User

Joined: Jun 2010

Posts: 6

Likes: 0

From: Ogden, Utah

I have done the swap. Mine is a manual and a 1989 BII. The generation 1 broncoII wiring is a little different then the second generation. I used a 91 exploder. Like Elder User said "get a 91-94 explorer". Put the truck side to side, if possible. Take pictures and notes while pulling the engines. Label all connection on the 4.0. This is a good time to upgrade you dash to a second generation dash. Most of the wiring connections, from old to new, will be on the drivers side. The plugs will be attached to the plastic inner fender, inside the engine compartment. The thing I did that helped me was I took the whole harness system. The engine harness, the light harness, and the dash harness. Since both dashes were out. I is a great time to swap to the newer dash.
Make sure you get a donor that is the same tranny as yours. Auto-auto and manual-manual.
Also if you have an explorer donor, do an axel swap as well. Rear 8.8 and the front Dana 35. How to do all of this can be googled. It sounds really hard and in volved. If you take it a little at a time it's not that bad.