This isn't the first time, so I know I'm not the only one to run into SBC 350 exhaust manifolds shrinking. Same manifolds, same heads, same sides, but the holes don't line up now. Engine has been out since early summer. Will they shrink more the longer I leave them off? Left side went on after it learned some new words, but right side doesn't even look like it will listen. Have tried my six-pound coaxing wrench, but it be cast iron so got the result I expected: zip. I don't think the gas wrench will help any, either. Cold when took em off, cold putting them back on, and again, cast iron. Maybe the heads grew, but that's scary. Think last time ran into this, had to use different manifolds, but that was long time ago and had plenty around to try to fit then and don't think even used manifolds off 350, might have come off 400. Does anyone know the cure ?