Short block Q's

I have a chance to get a mid/late 80's 4.0 block for cheap and am wanting to know if I can use it to replace my fubard short block and use all my current fuel ingection etc. I have a 91 xj w/ax15 trans.

you can use a 4.0 block from 87-90. only thing i can think that would be different would be the knock sensor bung is threaded and your 91 wont be, but you dont need it.

you will need the correct pilot bearing and you will need to use the flywheel from your 91 so the cps works proporly.