Does anyone know the specs of the GMPP extrude honed manifold. Im trying to find out what the diameter of the openings are where it bolts to the head and the one where it bolts to the downpipe. Reason being is that I bough a used GMPP manifold from someone on the site and I want to measure it just to be sure I really got a GMPP one not just a stock ss/sc one. Not that I dont trust the guy, I just want to be sure before I go through the trouble of swapping it just to find out it's not a honed one. Thanks in advance for any help.