I don't disagree with anyone on the fact that a 6 or 8 cyl would be a big improvement. But I'm not looking for a big improvement on power, just want to liven it up a bit. Things like an air intake and exhaust components are easy to find. However, I thought I'd ask to see if anyone knew of a supplier for internal parts. If not that's fine. I like my 4 banger. I've put 170,000+ miles on it with very few problems. It's just time for a rebuild. If I was building up a project jeep, a motor upgrade would be on the top of the list. This one's just my daily driver, and I put 100+ miles a day back and forth to work on it, I like the gas milage of a 4cyl.
Anyway, if any can help, thanks.