New Potential Project?

I recently acquired a 1986 nissan 720 in working condition with a good body for virtually nothing. My question is it worth it to try to fit the I4 from post 1991 jeep into to the engine bay of this little 4X4. My horse power would jump from 109 to 130, but I need some information. 1) What size of engine bay do I need to do this if I don't alter any fire wall? 2) what is the difficult in the swap If I change out the entire power train? 3) didn't wranglers come with an I$ option if Memory serves? 4) should I attempt this? The body is in suck good shape for a vehicle of this age (just one spot of rust on the drivers side rear fender)

that seems like way too much trouble to go through. if the thing runs just leave it alone and wheel it. cool little truck tho, my friend had one for awhile till the motor blew.