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1998 TJ/XJ Block


NAXJA Forum User
Hi all,

Looking to put a new 4.0 in my 98 XJ. I found a donor from a 98 TJ. To the best of my knowledge, I would need to use my motor mounts and oil filler adapter, the rest is all the same. Is this correct? Or is this not so much of a direct swap.

Thank you
If it's truly a 98 then you should be good to go with that!
  • XJ Cherokee and ZJ Grand Cherokee 4.0L engine blocks interchange.
  • 2000+ TJ Wrangler and WJ Grand Cherokee 4.0L engine blocks interchange.
  • YJ and 1997-1999 4.0L TJ blocks will interchange in XJ/ZJ
  • XJ/ZJ blocks, and the 2000+ TJ/WJ blocks do not interchange without significant modifications.
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.
Thank you both for your helpful comments. Hopeful to pick up the tj motor this weekend. I'll install and test before I put gaskets, freeze plugs and paint into the new donor motor of course