I have a problem got car started last night, in cold ass weather. But when it is shifted into gear it will not staying running. I know i might have to change idle screws on Holley or play with timing. Im a missing any thing. Would bad gas do that? Car sat for 5 months.

check the choke ??? ritchen up the mixture screws a half turn,,see if it helps...:texas:

Check for vacuum leaks. Does it run after being fully warmed up?

Sounds like the choke is set too lean. Make sure the choke closes when the throttle is moved off idle (cold), before you start it. The fast idle cam should come up too, to keep it running until the choke climatic spring heats up. Timing likely has nothing to do with it if it was running OK when it was parked. A little carb cleaner spray on the choke linkage may be a good idea too.