Brakes not good enough

[jcd9730]

So my 72's brakes just do not feel 'up to par'. Front disc, rear drum obviously. I installed power brake booster a year ago. Vacuum is subpar (maybe 15" to 17"). I have completely replaced the front pads, calipers, rotors, all lines except the steel ones, complete rear drum rebuild, etc. All flex line replaced. New MC, Booster, PP valve. EVERYTHING new except steel lines. Honestly, I don't understand the why behind replacing steel brake lines unless there is a big problem. But mine bleed fine.

It just doesn't feel right. Big brake kits are a BS waste of money (seriously, look it up, they are not useful at ALL on street cars). Long braking leads to lack of brake power (almost like overheating the drums), hard braking is just not good enough (I can lock it up, but again its at low speeds). When I'm driving, it just feels not good enough.

I know nothing about age of engine, etc. It is not original, but thats all I know. 15 to 17 vacuum is low, but low enough to cause brake problems? I had a 2001 mustang gt, and this truck is just about exactly the same quickness. So the engine is not slugish, but just brake problems.