Full-Flow Oil-Filter Kit from "Motor City Flatheads"

[crunch]

I have a '53 Ford flathead V8. When I overhauled the engine I installed the Full-Flow kit. I had to modify the oil pan to except the new pump and hose going thru side of oil pan, went fine as per instructions. I mounted spin-on oil filter in its original spot on head after adapting bracket. Primed system and it worked great. Car sat for awhile, (winter) and when I started it up no oil pressure. I'm wondering if there should have been a check valve between the pump and oil filter? If anyone could shed some light on this it would be greatly appreciated
Sincerely, Crunch