Try a search on power brakes. The search text-button is on the upper corner of the screen.
Basically, you've got a few decisions to make:
Will you stick with a single master or switch to dual for added safety?
The original trucks had single master and some came with power brakes using a hydrovac unit mounted on the frame rail under the passanger side of the truck.
If you go with a dual master cylinder there are companies that sell the master and bracket to keep it in the stock location. Or you can buy just the bracket and get your master from a FLAPS or junk yard. Or you can make your own bracket.
If you go with the dual master in the stock location you can also go with a 7" single or dual diapraghm booster. There are vendors that sell kits with the bracket, booster, master and combination vavle. These work great on trucks with automatics. With a standard the clutch fork will hit the booster so you'll have to change it for a bent 'vette style arm or upgrade to a hydraulic clutch set up.
Another option is hydroboost- that uses hydraulic pressure from the powersteering pump.
Another option is to put the booster and master on the firewall and change the pedal. Just like the other options, there are kits or you can cut the pedals, mounts, booster and master from the boneyard.
Will you upgrade the front to disc brakes? There are lots of kits out there to do it, basically, the kits are brackets for the caliper, caliper, a rotor. If you upgrade to discs go ahead and upgrade the wheel bearings at the same time and check the kingpins. Same thing here, you can buy just the brackets and find your own calipers and rotors (74-77 camaro rotors and calipers seem to work with the spindles and bearings and are cheap at a FLAPS) One issue here is bolt pattern on the rims. You'll have to decide if you want to use your stock rims or have two sets of rims and a univesal spare, or whatever.
I suggest doing a search here for posts on 'power brakes'. Then get a few hot rod magazines and look at their power brake ads, then go to a few vendors websites to see what they've got and how much they cost, then make a decision. I upgraded my fronts to disc and added power brakes in the stock location with a dual master with a kit from CPP. Next time I'll probably make the bracket and buy the parts from a FLAPS or scavage them from a junk yard.
Then there's the various valves you may or may not need- ie metering valve, proportioning valve, residual valve, etc...
I'm sure there will be other input. I'm not an expert so I look forward to seeing what everyone else has to say!
