"One-way" fuel line valve..?

Mike and Darter, thanks for the tip
As the check valve is already ordered, I will try it and if it's not efficient, I will install an electric pump as a cold start booster...

I have a '68 Valiant instrument cluster installed into my Demon, and it has a very nice on/off switch ready for use (initially the flasher switch). Would be perfect for a momentary fuel pump boost. :)