Yes, my car is a factory 400 & factory A/C car. The original A/C was replaced with a vintage air system by previous owner.
I'll check on the radiator cap (14-17 psi) and acquire the correct or a better one. As far as the fan spacer though, you say yours, also a 69 with 400 & A/C didn't come with one.
I believe like other FGF viewers indicated is currently sitting at about 50% in the stroud and 50% out or there abouts. Just seemed like the extra space near the radiator could call for a fan spacer like the ones that Ames Performance sells. If I remember correctly, it comes in a 1", 1-1/2", 2", then amybe also a 2-1/2" spacer.