I am trying to check my valve clearance ( 91, F2). I took valve cover off, and the pick up access cover. The Clymers says to align the "T" with the timing mark and have the "IN" and "EX" lined up with the valver cover.

I have a aftermarket position sensor as there are no marks on it at all. It has 9 timing (they look like chain sprocket teeth) when I align the 4th tooth, the "IN" and "EX" align up as in the manual. but. before I go and take out the cams to measure the shims in it, I really need to know if this is correct.

Anybody familiar with this?
Thanks