I did it. I cut a 4" hole in the top of the tank. Welded a homemade adapter ring to the top and dropped in a modified Chevy fuel pump module. The smog ref wanted the whole module in there to pass.
I put a 6.0 in my FJ62 and bought the MAF aluminum radiator. It only lasted six months before it cracked and leaked. I put the factory radiator back in and no problems.