I just bought this real nice pair of steel Ford 81T heads. LH & RH. Made in U.S.A. I believe from a 1938 truck engine. What are the big bulges on both ends ? Never seen that before . I suppose you could drill and tap for heater hoses but that is allready next to the radiator hose position. Then again they make it easy to remove the heads , a claw hammer, big chissel or small crowbar fit under them real easy . Any ideas ?