My 91 4.0 ax15 4x4 has a cracked head and has been leaking coolant into the oil for a long time and has around 300,000. So I was going to swap it out with a two-wheel drive 1999 4.0 auto. concerned about what pilot bushing I should use and if it will even work? pilot bushing for a 91 is different "19/32" diameter" than the pilot bushing for a 99 "3/4” diameter " I think anyone have any first-hand experience? Any other hurdles I may run into with just switching the blocks?