86 2.5 Mtx - New Wheels, Exhaust And Initial Cleanup

[sidepipe87]

Sounds good to me, I'll have to give that a try. When searching to find out what those coolant ports were numerous people said they would be hesitant to reconnect them adter they had been disconnected for some tome because the manifolds were prone to crack when removing rhem. I'll just give it a shot and see what happens.

[onlyinajeep726]

Hey, if you mess it up... good time for a 4.0 swap haha... But seriously, you should be fine.  If not, a manifold from a 2.5 TBI Jeep will swap on. 

[sidepipe87]

I wouldn't mind a 4.0 HO swap at some point but I understand the '86 firewall will either need to be "massaged" or have a portion of it replaced to fit the 4.0 properly. I didn't know the newer 2.5 TBI manifold bolted on. I'd assume they don't have the coolant passages running through them though, or do they?

[onlyinajeep726]

All 2.5's from '86 - '90 are TBI and thus have the same intake manifold.  It was in '91 that they went to MPFI.  That's one thing I didn't like about my 2.5 when I had it.  But if you ever do decide to swap in a 4.0L, let me know.  That's what I did with my '86.  The engine, harness, computer, etc. etc. all came from a '90 XJ.  It was a lot of work, but well worth it IMO.  I also had to swap in a suitable transmission because the AX4/5 can't be adapted to a 4.0L.

 

Another, simpler option if you TBI craps out is to swap in everything from a '91+ MJ/XJ with the MPFI 2.5L.  You won't have to mod the firewall or radiator support and you won't have to swap transmissions.