Wrangler vs Cherokee donor

[Carl]

Hi all. I want to replace the AMC 4.2 in my 74 Scout with a OBD1 HO. Maybe a stroker, maybe just 4.0. I have a 91 engine that is a candidate. It is almost complete but partly dissasembled. I think it came from a YJ because the power steering reservoir is remote from the pump. Before I start rebuilding this 4.0 I want to be sure this engine is the right one to keep my swap as simple (and cheap) as possible. Okay so here is the question: What are all the differences you guys know about between the Wrangler and Cherokee 4.0's that affect the swap? I plan to keep my T-18 trans and use the 4.0 serpentine accessories.

[yuppiexj]

The Wrangler 4.0 has the radiator fan centered on the engine, the Cherokee's engine driven cooling fan is offset to the passenger side.

Other than the PS pump,that is the only difference I am aware of.

[IH 392]

You'll have to adapt the crank sensor to your 258/T18 bellhousing too, they mount on the bellhousing and the T18 WILNOT bolt to the BA or AX bellhousings. assuming your going with the FI?

[Carl]

Good, so the Wrangler fan location is prolly best for my Scout. I like the mechanical fan because I don't have to run more amps thru the Scouts ammeter (fire!, fire!) for an electrical fan. I wonder how much juice the ECU and fuel pump will take? I just need to swizzle up a fan shroud somehow.

Fuel injection is desired so I can be more popular with my neighbors. I thought I would mod the Scout T-18 bellhousing for cps to save money. The sensor and flywheel came with the 4.0. I have a bell from a 93 Jeep with AX-15 to use as template- it should be the same cps location, no? Another idea I had- since the Scout bellhousing is longer (I think) maybe I could fab an adaptor to go between the AX-15 bell and the T-18? But then maybe the linkage would get tricky.

Thx and keep the suggestions coming! Carl

[Plechtan]

Advance adapters and Hesco both make kits to move the crank sensor to the harmonic ballancer. I think they cost about $250. Hesco also sells a wiring harness for the ODB1 setup. This is the same stuff that Mopar Performance uses in their fuel injection retrofit kit.

[Carl]

I got the complete harness with the Wrangler engine. I hope to mod it instead of buying custom to keep cost down. Same plan with cps. The worst part about having to do things on the cheap is it almost always takes much longer.

Today I learned a couple more differences between Wrangler and Cherokee 4.0. The Cherokee has a right angle oil filter mount vs the Wrangler straight mount. I'll have to check how close the oil filter is to the Scout engine mounts and see which style works best. The alternator mounting bracket is different too, but I haven't figured out why yet. I am trying to find pics to compare the two serpentine belt configurations.