You should be able to build boost with no problem with vacuum brakes assuming your idle vacuum, in gear, is 13-15" and everything is working.
If you ride the brake doing a burn out, you must lift off the gas and brake for a second or two before staging in order to recharge the booster...instead of being on and off the brake as you are staging...you can try bumbing into the second lite by using the gas to shove the car forward rather than modulating the brake pedal....
Be careful with those large rear cylinders..if the road is a little damp and everything is bled properly, the rear end will come around you before you know it at absolutely the wrong time. And, don't hammer the brakes when you cross the line, ease into them...so the weight transfer to the front under braking does not lighten up the rear too much and the big cylinders decide to act like the road is wet.
If you look at the cylinders you bought and the back side of the backing plate on the car at the mounting of the old cylinder, you will see there is a clip that holds them on..once you remove the brake hose and the shoes, etc, knock clip out and swap the cylinders...pull both wheels off but do only one at a time so you can look at the other side when you get confused putting the brakes and springs back on. A digital camera is a great help or a picture in a book.. A brake spring tool is a help but I always use a pair of adjustable pliers or vise grips to remove/install the springs...I do have the tool but by the time I figure it out, I general am finished using the muscle method...
Be sure the drums are round and the brake shoes are adjusted properly. Once you think they are well bled....come back and re do them a couple of days later.
I don't think you will have any trouble with a shortage of vacuum if everything is working correctly...have fun..you got off to a good start.
BTW, what's the elevation of the track at Wall? I was guessing about 2500".
