I currently about to swap my '88 2.9L for a 98 4.0l is there any good books out there that can help me with this?

 

Stick with a 94 or earlier 4.0L....

Post 95 involve a bit more wiring and you'd have to use the OBD-1 harness on it anyway (more money to buy swap-out parts) to avoid swapping over to OBD-2.

 

a wrecked doner truck for all the small parts would be a real good thing to locate before you start, it would not only give you the parts but would give a good visual idea of how they hook up and location, good luck,bob

 

The 4.0L used a different tranny, xfer case, and driveshaft lengths. You need it all. I also recommend grabbing the 8.8" rear end. That 7.5 (or 6.5 if you are really unlucky) is junk.