Jack, I know you've checked, but with the size of that bottom tank it sure seems like a good radiator guy could open up the front or back, TIG in some brackets and slide in a tranny heat exchanger coil, then TIG the front/back on to close it up. Might be cheaper to just get a new one from PRC, Griffin, Walker or..... that has the HX built in, then bracket your grill shell off of that.