This one is probably easy.......

I have a 66 GTO with a 67 400 cid 4-bbl engine. I have been told the fan clutch is weak and needs replacing. Do I get a thermal type fan clutch or a non-thermal type? Both are available. Oh yeah - it's an AC car with auto transmission if that means anything to the selection. Thanks.

 

probanly a thermal type, being an ac car. your local parts house would know for sure