Have a 73 k20 350. 1406 edelbrock carb. With the cold weather my truck hhas started running like crap when I start it cold in the morning. It will start up fine for a few seconds and then just started chugging to where it almost sounds like missing. Once it's warmed up seems to run fine. Played around with the choke, didn't make a difference, whether the choke is open or fully close it runs equally like crap until Warm. Any ideas?