Need some advice 4.0 swap or no 4.0 swap.

[jkufen]

I know there has been many threads posted about the 4.0 swap and this is another one . Just curious next summer I am going to be make the transition from daily driver 86 B2 to a rock crawling 86 B2. Well am going to be tearing it down to the frame and building it back up. Right now I am sporting the 2.9 like many others and I know many people hear have had great success with them. Just looking for some different opinions on here but I have an extra 2.9 that came out of a ranger and I have the 2.9 in my b2 I was thinking about taking the 2 engines and rebuilding them to have 1 practically new engine. Or I could go find a donor explorer and use the 4.0 out of it. This is where I am back and forth. I have 2 engines now that I own and are paid for and all I would do would be rebuild it and slap it in and everything will wire up perfectly and so on or I could go out and spend 700-1000 dollars on a donor explorer and use the 4.0 out of it, then rebuild it, replace what needs to be replaced, swap out the dash and wiring and put it in. Just saying that last sentence all ready leaned me more the the 2.9 rebuild. I know 4x4junkie here has had success with rock crawling the 2.9 with 35" tires. I will use the d35 and 8.8 rear out of the explorer but the local parts yard said they'd give me both for $250 and that is still a long way from the $1000 I would send buying an explorer. I don't know decisions decisions. I have until next summer to figure it out but I have a lot of other modifications I have to hammer out too. Just curious what you guys think.

 

[PetesPonies]

we are really talking about something that might happen next year?

 

[jkufen]

well the build won't take place till next year but collecting parts is right now.

 

[work_in_progress]

you think like me, i plan ahead way before go time!

 

[jkufen]

Yeah I have too. I don't have a lot of extra cash so I have to do things over a long period of time so what I planned was the get the engine and go ahead and rebuild it now. Then in a few months I would get the axles and rebuild them. Then so on and on. I guess from the lack of responses I'll just keep my 2.9 and rebuild it.

 

[country0001]

The 4.0 is the only logical way to go. It is totally awesome in the B2. If you can find a beat up 91-94 explorer 4wd, you will have everything to make your B2 the way it should have been.

I do not regret my 4.0 swap, it was the best thing I could have done for my B2.

 

[4x4junkie]

^^
I tend to agree.

The 2.9L is a decent reliable engine (and I don't see myself pulling it out as long as it continues to run well), however I wouldn't rebuild one when swapping to the 4.0L is no more effort aside from the ECM swap and wiring (which is greatly simplified by the dash swap).

Though the two engines are within 20 HP of each other at peak, the 4.0's far broader power curve fully trumps anything that the 2.9L might have to offer (driven at too-low RPMs, the 2.9L feels lethargic and can actually suck more gas than the 4.0L. Some have reported significant MPG increases after a 4.0L swap because of this).

 

[70roadrunner]

I am in the middle of swapping a 4.0 into my B II, im doing a "no splice" swap. ALL of the wiring from an explorer, and an 89 front clip on my 84. also 89 xlt interior. yes, it is a lot of work, but I think it will be worth it in the end