My apologies. 1965 Barracuda Formula S. The adjustment is frozen. I have sprayed it with nut buster several times, but can't seem to get it to loosen. Any ideas of how to get it to break free.
A fair number of folks on FABO like PBlaster to deal wiwth rust. I prefer KROIL, as do a minority on the board. Clean it, wipe with a dry towel and put a small amount of either recommended product on the nut and threads that seem to be fused. Let it set overnight.