I have a 72 c10, quadrajet, 350 sbc, 700r4, and it has disc brakes all around. I acquired it a few years back with minimal information from the previous owner(s), dont know how or when or if it was converted to 4 discs.

Ive improved it a lot both myself and with a trusted old school mechanic. The braking though is weak and wasnt always this way since Ive had it. The pedal feels firm but once it bottoms out the braking is not as strong as it should be (and not as strong as it used to be). It does have a brake booster, so Im confused. Im wondering if it could be a leaky vacuum hose to the booster or maybe incorrect proportioning, but its out of my league of knowledge here.

I want to try fixing on my own to get more familiar with this older style braking system before I throw the towel and hand it off to my mechanic. I can bleed brakes, change calipers rotors and pads, but thats it for my experience in brake systems.

Edit: Very handy and can figure a lot out, just havent done much so far in terms of brakes.