Crankcase pressure

a vacupan setup ,with mufflers is not good. they will back pressure the motor and cause oil to leak from breathers and push dipstick out also.
I know of two racers with same problem, one disconnected his vacupan system, no more problems, other guy spent $1100.00 on a vacuum pump setup. just run breathers. if you run open headers, then use a vacupan setup.