I love pontiacs but if you going to try to use this in an xj, I'd seriously consider selling it and try another engine. There're wider and heavier than sbc. They use a buick,olds,pontiac bellhousing pattern so youwould have to use a adapter or swap in a th350 or th400 that has had the output shaft changed for a 4wd. No th350 0r th400 bop trans ever went into a 4wd so I doubt they would have the right spline count. They do have one feature that might help you out. The exhaust point almost staight down, so that may help with exhaust. I'd give aa a call as well. They may be able to help you out but my guess is that if you try this you'll being doing alot of guess work and custom fab work. If you do get this in it'll definetly be cool.