Roger I have a 7" power booster on my '32 roadster with 4 piston wilwoods, save your money its not needed, I have a buddy who has built a lot of cars and agrees, the power booster is just not needed on that light a car much less that little 7" booster doesn't add to much to the performance, my '37 has the GM calipers and a dual 8" booster and I feel since the car weighs a 1000 lbs more its still probably not needed but it does stop well, if done again I would never fall for the thought a booster is needed on a roadster. I have also cut 2 'glass floor boards out for master cylinder doors, if done again I would use a hole saw and cut a round hole with a round door under a floor mat, easy to do and you only need to be able to get a small funnel through the hole, you can take the bail off from underneath, for some reason I had in my head you have to access the whole dang master cylinder, its not needed just a small hole (1 1/2) is about it, just big enough to see the fluid level through, it looks better and its easier to do.