52pu
Vacuum is 21 and steady.
Compression is 7(whatever) on all cylinders here on a german gauge - don`t know how to calculate that in US system.
I have a Corvette style (splitted stock)header and both pipes run side by side along the way where the single stock pipe was.
You are right with the donut, it is a bit loose.
I have to tighten it from time to time. But I never thought that it might have that big impact.
Frank
