Has anyone here installed one of the after market power brake set up that uses a single diaphragm 9" booster? I have and I'm not happy with the amount of assist it has. Ford used an 8" dual diaphragm booster, which is like having a single 16" booster. Any feedback would be appreciated.
It's installed in a 68 Coup with a 289, with a very mild cam. The manufacturer (A big name in the industry whose name will remain unmentioned) said I need at least 15" of vacuum. I'm at 4000 ft elevation, 15" of vacuum in drive is not going to happen. Even under deceleration which increases vacuum to well over 25" the brakes still lack assist. I have 4 piston Kelsey Hays calipers in front, all new brake components in back and all new lines and hoses. I'm considering installing a factory replacement booster, but I can't stand how close the MC ends up to the shock tower. I was mainly looking to see if anyone else has had the same dissatisfaction as I have, and what they did to remedy it.
A friend of mine did in a 66 convert ,same problem you have .He has since pulled it out and gone with one made in Orange Calif. ,i can't remember the name of the company but he said the difference is night and day.