Hello everyone. I have recently completed my '67 Skylark drive train project. The new motor, trans and rear end are in the car. When doing the rear end, I switched from the GM 10 bolt to a new 9". When I had the rear end made, I had them put the rear disc conversion package on it. Before the project started, the car already had front disc brakes on it. I left these alone, and hence the car now has 4 wheel discs on it. After the first ride, I noticed that the pedal is rock solid, but the car is slow to stop. My first assumption was low vacuum do to the nature of the cam size. I have since installed a canister to help support the booster. This only made things slightly better, if much at all. I am wondering now if I need to consider a different master cylinder, or try a proportioning valve in the system. I was wondering if anyone out here may have run into this situation, and has any suggestions on where to go from here. Good news is, she runs fantastic. Now all I need to do is get her to stop. Thanks for any feedback!