brake problem--need help!

[lnirenberg]

When I bought my '61 Bel Air it had a cheap front disk rear drum setup that wasn't quite doing the job. I swapped it out to a 4 wheel kit from SSBC and that would do it. I drove a bit last fall and thought the pads the setup came with were too hard and thought I had the fix in a softer set. Drove it last week for the 1st time this year and there was no improvement. The car is at a very good shop in MA and they feel the booster is undersized. The car came with a auxiliary vacuum pump that runs whenever I hit the brake pedal and I had thought this was to boost the power brakes. Now I have no idea what the pump is doing. The problem with a larger diameter booster is that it will hit the driver’s side valve cover. Thanks in advance for any ideas you have for fixing this. (see attached pic)