What does the crank pulley read when the cam marks are aligned? Are you off by 360 / # of cam sprocket teeth * 2? e.g., if the cam marks align at 4.5* ATDC at the crank and there are 40 teeth on the cam sprocket then you're probably off by a tooth.

Are you measuring with the tensioner set?

Sixto
95 S420
87 300SDL