Thanks William,
I was looking in the M40 section since my car has a TH400. My car is a '68 so the plate and screw is shown on UPC M35 A20 in the AIM.
Can’t find any reference to what type of finish the screw is. HBC sells the screws in Silver Cad but I’m not sure that is correct. If I look real closely at my screws I find no trace of Silver Cad. I’m guesing it was a phosphate finish.
Thanks,
Bob