I got a 3 piece heater with my truck project that I disassembled, bead blaster free of old age and repainted inside and out. It was working when the cab was pulled from the truck last year. Knowing that, I did a good detail job and was ready to check heater off of my long list when I saw pictures of a different style heater in ann of the other 55-58 task force trucks. Am I correct in thinking there was two different heater options for these trucks? Anyway, I picked up a one-piece type round-core heater and restored it too (just in case) but now I am not sure wich I want to use. Knowing if this was a good option or something that is not a good upgrade will make my decision wich to keep and wich to ebay off.