Originally Posted by Timmy69
ive read alot of swaps using the cherokee but nothing on grand cherokees i wasnt sure if it would make a difference or if it would pretty much be the same
If your '89 has the AX15 trans, it already has the mounting hole for the crank position sensor. If not, you might want to consider putting the entire engine and trans into the Wrangler. If it does have the AX15, the flywheel will need to be changed from the cherokee because of the timing marks for the fuel injection.
Like I said, if you have the donor car right there, it will not be that hard.
The Grand Cherokee just has more cushy stuff in it. But the wiring harness is similar. You will be removing all the ABS stuff from the harness. There will be a lot of wires left over, because it doesn't take much to make the engine run.
Lots and lots of threads cover this subject. Just start reading before you dive in.