Sorry If this comes up as a delist tried to post from my phone earlier. I have a 1970 b body air car however the air parts in the engine bay are gone and my heater core is bad. Can I install a standard non ac core in my heater box and use just the heat I will later install a classic auto air system maybe next season but I want heat for fall and the correct ac heater core is nearly 300 vs 58 or so for heat only. Will they interchange without modifications? Thanks in advance