HEI conversion problem - any input?

For your small block, you can buy a complete HEI distributor for $45 on ebay (skip white, etc). For that price, keep one in the trunk or for garage testing. Buy the Harbor Freight in-line spark tester ($4 on sale). Have someone watch it as you try to back out of the garage. If the engine stumbles while the spark is still flashing, it sounds like a fuel problem. Trying shots of starter fluid usually verifies that. I have kept engines running with that when the electric fuel pump seized.