Ford Repair: 88 ranger engine swap, swap kits, cab 4x4

Question
Nice name!!
I have a 88 ranger ex cab 4x4 11x33 tires and  2.9.
I have replaced the engine 2 time and it just dont have any power.I would like to put a 4.0 in it I have found 1 in a 91 explorer and 1 in a 98 explorer with 65,000 miles.
I would like to get the 98 but I am not sure if it would be harder to convert it over.
If you have any experience with this  i would appreciate any info I can get as far as problems I will have to overcome to get it done!!!
Thanks
Steve H

Answer
Steve-

  I wouldn't go with the '98 motor if I were doing the swap.  It's a completely different kind of motor and likely a nightmare to swap in.  If it were me, I'd just swap in a 5.0L and be done with it.  I've seen it done quite a few times so I know it'll work, but I don't know where people got the swap kits.  I do know that a company called Kaufmann Products used to sell a kit, but I'm not sure if they're still in business.  Hope this helps.

Steve