Welcome to the forum.
I've never seen anyone use the factory guages with a 4banger to V8 swap in a TJ.
Aftermarket guages work great though.
This member did the same swap a long time back from 4banger to LT1 chevy engine....
Shoot him a pm and pick his brain. ......MR.CLIFFORD
Here is a video of his gauges .....
YouTube - str8rage's Channel