[MidOHasp]

cut the neck off, get a thermostat housing, figure where you want the neck on the tank, take it to a radiator shop, have them braise the new neck in the bottom where you want it and close off the old hole. Run a piece of rubber hose from the neck of the tank to the thermostat housing (90 degree works well). Wash, rinse, repeat. I did this - not the most fun I've had, but it worked. Took a P.O.S. FE tank from a 390 , had to do all kinds of body work on it, etc...but it looked perfect. For about a week, then we got air in our system and the thing came under serious pressure - more than the cap could vent, and we blew the tank up. It didn't separate, but it did round out real nice.