I just recieved my header and downpipe combo from clear image automotive and i bought a new gasket for the header from my local dealer. I noticed that the gasket dosent seem to match up properly. I have 1 and 3/4 inch primarys and it seems the gasket is made for 1 and 5/8ths. I checked out the part number and it is the part # for the gm extrude manifold. Are the primarys for that smaller than stock?