couple of questions
 

I have a couple of problems that maybe someone has an idea about, the first is at idle I pump the brakes and the car doesnt stall but the the idle will lower alot, it seems like vacuum to me, but i am not sure what to check.
The second problem is the carb stutters, it seems to be in between 2000 and 3500 rpm, the car will buck alot and only stops if you floor the gas. It does this in all gears. Thanks for any help you might have.

To me, the carb problem sounds like the accelerator pump might be shot but RX7Carl or Sterling can tell you more about that.

The brakes problem might be something to do with your servo, it could be venting (it works off vacuum)

it takes power to charge up your brakes, just like turning on the A/C on a low idle, and the same thing happens to my Rx-7 at about 2500 rpm i think it is the air inlet isn't open enough for the air/fuel mix to be right,

im not a pro at this but this is what i think ;-)