What I soon found out about using jigs. Make sure the jig is the same bolt hole pattern to the hub plate for your engine. Set them in aliment with each other and take a close look. The holesshould match pretty close. Youcan check that too with tight fitting bolts, drill shanks or pins. I have found out that after you drilled the first hole is to use a tight fitting bolt or round pin to locate it. Then drill another hole on opposite side and pin that one also. Drill & pin as you go....they come out better. Balance also.

Capt,n