'88 to '90 Swap

[cozee]

I have an '88 2WD, 4.0 w/stick. Needed a rear and bought a '90 2WD, 2.8 with bad automatic. After getting the '90 home we decided it was definitely in better shape than our '88. Planning on swapping out the 4.0 and stick and putting it into the '90. I am assuming this is pretty much a straight across swap. Anything to look out for?

 

Thanks!

 

Cozee

[JeepcoMJ]

yep, straight across. but the 90 can't be a 2.8...that's the v6 from 86. it is a 2.5.

 

 

but yes, pretty much direct swap. you will need the dash harness, engine harness, cooling system, all electrical components, fuel pump/sending unit, engine, trans, and driveshaft(s) from the 4.0.

 

I recommend doing a 4.0 swap while you're in there. is the '90 already 4x4?

[cozee]

Thanks! I knew it was a 2.5. Don't have a clue why I wrote 2.8. Both trucks are 2WD. I would have just gotten rid of the '88 but my son is a bit sentimental about it. Since he was 13 he had driven it almost every day to go fishing at the river about 2 miles from our house. He is now nearly 19 and was really wanting to keep the old truck as a second vehicle but when the rear end went, we thought it was time to put it down. Found the '90 at the last minute for the right price. He likes the '90 as it is nearly rust free which is quite a find here in east central Illinois. He wants to keep it 2WD so that it will stay.

[JeepcoMJ]

Thanks! I knew it was a 2.5. Don't have a clue why I wrote 2.8. Both trucks are 2WD. I would have just gotten rid of the '88 but my son is a bit sentimental about it. Since he was 13 he had driven it almost every day to go fishing at the river about 2 miles from our house. He is now nearly 19 and was really wanting to keep the old truck as a second vehicle but when the rear end went, we thought it was time to put it down. Found the '90 at the last minute for the right price. He likes the '90 as it is nearly rust free which is quite a find here in east central Illinois. He wants to keep it 2WD so that it will stay.

 

 

k. the rear end in the '90 may have too deep of gears for a 5 speed on stock size tires....4 cyl/auto should be 4.10 or 4.56 but may still be just 3.73's

[cozee]

Won't be a problem as we have a set of taller tires we can use.

[JeepcoMJ]

Won't be a problem as we have a set of taller tires we can use.

 

to take that back to stock set gear ratio you will need 32 or 33 inch tires, unless you have a built motor that can withstand the RPM's.

 

IIRC hornbrod is running 4.10 in his with 31" tires, but he's got a nice setup for that.

[Pete M]

I would most definitely drive a 4.0/stick on 31" tires and 4.56 gears. :D and I'd smile the entire time. :D :D :D No different than a v6 Rodeo running factory 4.30 gears and 29" tires.

 

 

oh, and a blown rear axle is a pretty poor reason to kill off a truck. :( A hundred bucks and an afternoon's work and it'd be up and running again. :thumbsup:

[cozee]

oh, and a blown rear axle is a pretty poor reason to kill off a truck.

 

D35. Has had 2 replacemnts since I've had the truck. Besdies, there is 240,000 + miles on the truck with plenty of body rot and the frame is getting questionable rust wise in the rear. The '90 is definitely a far better truck requiring far less work. Besides, I just may put it in the shed and when I find time, drop a 302/auto with a 9" in the rear and make a nice little rat truck.

[mjeff87]

you really don't have to swap out the dash/cab harness unless you really want to 'cuase it's a bit newer and may be in better shape.....just need to swap the engine harness and 4.0 ECU (since your keeping it Renix).

 

Jeff

[JeepcoMJ]

you really don't have to swap out the dash/cab harness unless you really want to 'cuase it's a bit newer and may be in better shape.....just need to swap the engine harness and 4.0 ECU (since your keeping it Renix).

 

Jeff

 

 

that *might* be true. IIRC 89/90 are interchangeable, and I know 87 is not interchangeable with 89/90, but I don't know about 88.