help with drag car brakes

I would like some help with the brakes on my 65 nova drag car. It has four piston calipers on front & rear. Master cylinder mounted under driver seat. The problem is you have to continually pump them to get brakes. Best opinion i have so far is the 1" dodge master cylinder is just to small to get the volume to the calipers. Need some input on what needs to be done. Have bleed them until there is no way air is the problem and it has those small valves in the lines. It be scary feeling at 150 mph.
thanks

You need more volume 1" bore is not cutting it when running 4 piston calipers front and rear you will need a 1.125" bore master cylinder . When using single and 2 piston calipers in the front and 4 pistons in the rear you should run a 1.032". Also Be sure you are using the correct residual valves since your master cylinder is mounted in the floor. hope it helps.