What brake booster to use on 69 cougar

Hi I’m new to the forum. I Have a 69 cougar with a 390 wanted to switch to power brakes but looks like a power brake booster will not fit any suggestions? :wall:

It fits fine, no issues. In 1969 either a Bendix or a Midland Ross booster was used. Performance of the Midland booster is better IMHO. All the same parts as a small block Cougar with power brakes. No difference at all.