2.8-4.0 Swap

[jimoshel]

Know it's been done a dozen, or more times but I can't find any info.Would like read up on how someone else did it before I start. If any one has a link it would be much appreciated.

1986 MJ, 2.8, AX5, 4WD. Going to replace the 2.8 with a '90 4.0. Not sure yet but may replace the AX5 with a AX15

[randomguy310]

you will have to change the trans and transfer case too if I am not mistaken

[GirsMJ86]

Shouldn't be anything special so long as your firewall will accept the 4.0 block. The firewall is not curved to fit the 4.0 in 86 rigs unless it was end of year and they started implementing changes for the coming year when the 2.8 was replaced with the 4.0. If your firewall will fit the 4.0 then it is a relatively simple swap, otherwise you need to massage it or hack it up and weld in the section from a 4.0 rig.

 

Just swap everything that you can along with the 4.0. The header panel, radiator, hood, and all that is different as well don't forget.

[neohic]

Couple of good 4.0 swaps from Drahcir:

 

http://comancheclub.com/topic/28613-project-drahcir49%E2%80%9Dtwo%E2%80%9D/

http://comancheclub.com/topic/29853-project-damien/

 

... wonder if he ever finished them?

[jimoshel]

Thanks Ben. Just what I was looking for. I know I've read over a hundred articles on the subject here on CC but when I looked for them couldn't find anything.

[neohic]

I had it bookmarked just for these couple pictures showing the difference in firewalls:

 

 

How does the fire wall look compared to anyone’s newer MJ/XJ? Does it look like it is already updated/clearance for the 4.0? ->

... If you look on the right side of the area above the transmission tunnel, there is a "step" at the top of the newer one that allows the 4.0 to clear it, whereas on the older engine its not there...

 

... he did a great job of showing how to dissect a front crossmember in the "Damien" thread too.

[mpace6a]

Thanks neohic...was looking for that quote of mine  :thumbsup: