What is the difference?Just the dowel pin length? Thanks.

 

The core is a bit different because the Optispark is driven off the cam. Other than that, not much else is different other than the dowel pin lengths.

-Mindgame

 

What exactly is different about the core? Can you run one in an lt1 safely?I was thinking that on my car the top timing gear actually drove th opti. Thanks again.

 

The difference is in the center hole on the face of the cam. The hole size depends on the distributor shaft used (early or later). You can read and see the differences at this site, http://www.automotiverebuilder.com/ar/ar99928.htm

Still have the stepped snout like all 88-up cams, just the difference in the "drive-hole".

HTH.

-Mindgame