I resently twisted the frame on my lifted 2000 xj. Then wile crusing Craigslist and found a stock 87 mj with a blown 2.8 v6 and I was wondering what all can i swap out of the xj and in to the older mj

 

86 had the 2.8
87 had the 4.0

most everything from the xj should fit with some work, but putting a 4.0 in place of the 2.8 would be tough as the firewall was changed to accommodate the longer engine block in 87.

 

You could put the engine from the 2000 in with older wiring, but doing a complete 97+ swap is a TON of work. Making different holes in the firewall for the different steering columns, all wiring, etc. However I just swapped everything from a 93 XJ into an 87 MJ and that was easy, everything bolts right up, and that would be the same for any 96 down.

 

It's more than just holes on a 2.8 engine bay. The entire firewall is different and the engine bay is too small to fit a 4.0 without extensive modification to the engine bay. It's easier to just swap in a better GM motor. There's a few options that will bolt right in.

 

A vortec 4.3 would be neat

 

A GM 3.4L V6 is a plug n pray replacement/upgrade for the 2.8L
A BFH would get the bulkhead adjusted to squeeze a 4.0L in.
Maybe consider an LSx swap tho..

 

Ghetto

 

Rustys makes motor mounts those now so go 4.3

 

Uh, not sure what you're trying to say.

 

Rustys makes the motor mounts for the 4.3 to go in the Comanche along with a few 9ther Chevy motors

 

Ok. It was just worded funny. No worries

 

Yea was trying to use the ole smart phone as a computer doesn't work to well lol

 

it doesnt take that much work to put a 4.0 in the 86... the area on the firewall needing to be clearanced isn't that substantial. A very manageable swap... other things would be radiator mounts and core support... trans crossmember will need new mounting holes as well. More than likely a custom length rear driveshaft too.

 

None of this changes the fact that the 2.8 wasn't an option in 87 so either the year or the motor is wrong. If it's the year then a 4.0 is a very easy swap, if it's a 2.8 then a 3.4 GM V6 is just as easy, a solid motor, and an infinitely better choice than the 2.8.

 

Had a 2.8 in my 84 cherokee definitely a junk motor even though I could beat a 4.0 off the line from 0 to about 20 mph lol. No matter how many gaskets/rtv I threw at it a month later it would start purging oil out of the valve covers again.