Great thanks for the info. That is good logic and I called my service manager who ive delt with in my old position as a apparatus supervisor for my FD for our GM ambulances and he seemed to think it may work so he is going to try and submit the thermo caused the rad failure process.
If not I think I will just do it myself. $150 rad that Im sure will be better then the garbage GM installs. WIll prob use the updated GM thermo just to be sure to not use a old style its $40ish. It will save me $250 for the adjusted price they are helping me with. ($1000 from the non adjusted price if I just paid cash)
Looks easy enough remove top cross member, unclip from Condensor, drain coolant, remove shroud bolts and hoses remove trans linesx4 and lift out. 2 or 3 hours goofing around