Im looking for some info about the differences in the cams between an 89 b2 head and the 93 b7 head? To make a long story short I received an 89 b2 head complete from the boneyard and used it on a b7 block. The car runs like its out of time even though the marks are dead on. Is the cam keyway different on these like on the a6? Any help would be great. TIA