jeefersjeepers

Hey y'all.
I want to Eventually swap in the "upgraded" 4.0. I want one as new as possible without the distributorless ignition. So 96-99, right? It's got slightly better torque at a lower RPM, and marginally better overall HP. I want to rebuild a motor so I have it ready when my current motor decides it's finished: (pushing 250,000 miles)

Current Jeep:
1992 Laredo
1992 4.0 HO (with 99+ intake)
4wd

The problem is, I have heard of people swapping in the newer motors into older Jeeps, but I have never seen any write-ups.

Any links?
Swapping from OBD1 to OBD 2 sensors?
What stays on the newer motor, what gets swapped with a fitting from the old?

Thanks guys

cruiser54

XJ Cherokee and ZJ Grand Cherokee 4.0L engine blocks interchange.

2000+ TJ Wrangler and WJ Grand Cherokee 4.0L engine blocks interchange.

XJ/ZJ blocks and 2000+ TJ/WJ blocks do not interchange without significant modifications. (1991 to 1995 YJ and 1997-1999 4.0L TJ Wrangler blocks will interchange in XJ/ZJ and visa-versa).

TJ/WJ 4.0L Engine blocks underwent clean sheet design changes effective in the 1999 WJ Grand and 2000 TJ Wrangler. These blocks are not interchangeable with XJ/ZJ engine blocks. The reason is motor mount bolt holes and belt driven accessory mounting bolt holes are in different locations, or not present at all, TJ/WJ vs. XJ/ZJ.


XJ: "Regular" (not Grand) Cherokees 84-01
ZJ: Grand Cherokee 93-98 (Gen1)
WJ: Grand Cherokee 99-04 (Gen2)
YJ: Wrangler 87-95 (Gen1)
TJ: Wrangler 97-06 (Gen2)