I have an old Matco leak down tester. I tested cylinders 5-8 at TDC compression stroke. Unhooked from cylinder: 30psi into tool (left gauge) ~29psi right gauge (hey it's old) Hooked up to cylinder: right gauge was reading between 20-22psi, which if I understand correctly is 33% loss. IMPORTANT: The car was coldish... I did all this with the upper intake and valve covers off so by the time I got to everything, it wasn't anywhere near operating temp. Could this cause this much blowby? Because I second guess everything, I went out and bought a harbor freight leakdown tester. Same psi, the leakage was right around 30-35%. No air escaping through radiator, no air from intake manifold, I hear rushing past rings into crankcase. This engine was just built with all forged internals by a local machine shop that I've heard from several people is good. I'm going to talk to him tomorrow, but I wanted to share what I've found first and hopefully someone unbiased here can clue me in to what I might be seeing. I know that he asked me when I had the bottom end built if I was going to boost it. I said maybe in the future. He said he would install the piston rings a certain way so that it would be boost ready but guaranteed me it would not affect NA performance and functionality. What he hell could be going on here?