For my '66 289 the OEM timing chain cam sprocket had a spacer behind it so that it wouldn't hit the block. The replacement (Cloyes set) has the spacer length cast onto the sprocket (NAPA's is just the same). The original spacer is short of impossible to remove. With it still in place, the dowel is not long enough to drive the fuel pump eccentric and of course the crankshaft cam wouldn't line up. Three questions: 1. How can I remove the spacer? -or- 2. Where can I buy a timing chain set with the OEM sprocket dimensions? -or- 3. Can I have the Cloyes unit ground down to match the original? Many thanks in advance for advice from you experienced experts.