I'm building a '57 292 for a project and am installing a Comp cams camshaft in it. Spec are, gross lift both I&E .471      Duration @.015 tappet lift 261 Intake & 267 Exhaust      LSA 108* . My problem is this, when degreeing the cam I have to "retard" the cam 6*, my multi keyway timing gear set can be adjusted to 8* advance to 8* retarded so I,m not maxed out but 6* sounds a little far. What do you all think? I have checked and rechecked my process 3 times and it comes up the same. The cam card says I need a 108* intake center line. 
I did a on-line chat with Comp cams tech guy and he said it "sounds odd but strange things can happen with custom ground cams" & "just put it in and see how it runs" Someone on another site suggested checking the exhaust side to see if the cam was ground right and I guess I could figure out how to do that working off of the cam card but would I have to check each intake and exhaust lobe? Am I just over thinking?