[davepl]

If you can find AN ACTUAL ORIGINAL GM HEI, then do it. The cheap ones are garbage, at least I've have 2 bad ones out of the box before I learned it.

If looking stock matters, and even if it doesn't, I'd just use a Pertonix module in your original unit. You may have a point gap issue to check, and that'd eliminate it, but gap them before you throw parts at it. Dwell can cause hard cold starts.

But sounds like you're missing some stuff. Is your choke set? Is your choke pull-off door gapped correctly? Heat riser working? Heat stove and chimney in place? Thermac valve working properly?

All that stuff needs to be there in proper working order for it to run right cold.