LS motors are ridiculously easy to get your hands on these days. Don't get me wrong, old school small blocks are cool as hell (especially w/ Truck Avengers. Best carb IMO,) but Vortecs w/ EFI just work so much better off camber.

Find a nice 5.3 from a wrecked Tahoe/Silvy/Burb/whatever and throw it in there. 4l60's, while considered relatively weak, are more than adequate for a stock-ish motor in a super light XJ. Use a t-case of your choice, and you're good to go.

 

I would skip the np231 for something bigger.That much power i see it breaking first.And from the factory no one used the np231 on any v8 just 6 cylinders.If money is tight a np241 is a step up but if you got the money a flipped dana 300 or np205 would be better to have.

 

You will regret your decision to swap that motor in to an XJ for sure, for a lot of different reason's.

I had a fresh spare engine in the shop a SBC 364ci., Full Forged Rotating Assy.3 9/16 stroke, Complete Roller Motor, balanced, Dart 215 Pro 1 Alum. Heads, pump gas motor (93oct.) 575 HP engine dyno Pro built. This was the spare engine for my wagon before I went with the Dart Block/Heads, Twin Turbo, Air to Water Inter-Cooled, Fast FI setup it now has 1500HP.

Thought about putting this in my XJ but after a very small amount of research found out on what a poor idea it was.......So I had a 4.0 rebuilt to a race spec. by my engine builder machine work/balancing so on.

 

This may be a dumb question...

But is it possible to use the stock gages and have the interior work perfectly normal when one swaps in a v8?

 

The older xjs it shouldn't be hard but the 97 up would be harder to do.I would use it as a reason to use aftermarket gauges.Factory gauges are not as accurate as some of the aftermarket ones.

 

Novak makes a computer to piggy back off of your existing one so you can run gauges.

 

I know what you mean. But I want to be different than everyone running a stroker and a v8 will be awesome. Mine won't be as crazy as your motor was but still a lot. Plus working at a shop and being able to do everything between me and some buddies, it's worth it. Worse comes to worse ill part out and restart somewhere else

 

I ran the stock senders in mine. Works fine.

 

Drop the pan and change the bearings... inspect the head for any cracks under the 710 cap.

Been there, done all that! See my sig links.