After my conversation with Hotrod Lincoln i reset the timing using a static timing method he suggested with a test light. Worked easy and the engine runs smooth. The cracked phenolic block led me off on a wild goose chase and i think the timing had shifted because the bolt holding the distributor had loosened and allowed the distributor to turn and the timing to shift.
Thanks to all for your suggestions and especially to Hotrod Lincoln for his willingness to have a phone conversation to discuss.
Frank
