I have a 1957 Chevrolet 1/2 ton truck that I have restored nearly single-handedly, as close to original as possible. My only variances are a 1960's V8 and a 1980's 5 speed manual transmission.
I initially converted my master cylinder to a manual dual cylinder, but I wasn't pleased with my stopping ability. I then purchased a power brake conversion that stayed in the original location but have had loads of trouble with it as well. I've adjusted the rod between the booster and master cylinder, going from too much brake to not enough and never finding the happy medium (even purchased a tool to adjust it). I currently have brakes at times, and none at others (quite a thrill ride and too dangerous for me to risk wrecking my labor of love).
I've read a dozen articles on brakes, and still can't get them correct--bled system many times, new brake line are not above the master, residual check valves in place, etc. CPP tells me that due to the manual transmission, my only other option is a unit that mounts to my firewall and replaces the brake pedal--that is more hacking than I want to do on my truck (want to keep it as original looking as possible).
Any ideas?