Lets see here:
Regarding the vacuum line to the power brake booster. You shouldn't have any higher RPM with the line connected to the booster then when the line is removed and plugged with your finger. That tells me you have a vacuum leak on the booster or around the grommet on the booster that the check valve plugs into. Disconnect and plug the vacuum advance line going to the distributor...that will lower the idle more. I'm thinking when you dropped the new distributor in, it's advanced a tooth or two too much.
Try plugging the vacuum line going from the carburetor to the booster as well as the line going to the vacuum advance canister. The idle speed should be lower. When the idle lowers adjust your mixture screw to gain the highest rpm and then back off the idle screw more to lower the RPM'S. Let me know what happens and then will work from there.
Joe
