New to Fourm, Running bad, only in the morning

[onelow69]

Long time lurker, new to your post . I want to thank you all for the help you gave me over the past year with all the threads of info. Now I need some help, I have 69SWB 350, stock to mild cam, 400th and this is my problem. About 2.5 month ago I started having this real strange problem, when it started to get cold in the morning. I would go start my truck up and it would run fine for about 4 to 5 minuts then it wood start to run like it was missing or starving for fuel and slowing down until the engine wood die, but if I gave it gas it would stay running as long as you brought the idle up with you foot, but once the truck warmed up it ran fine. So the quest was on to fix the problem. #1 so I swaped carbs Eld1406 for a Eld1406, so I waited til the next moring to start the truck and it did the same thing. Ok, lets change dist HEI for HEI, waited til the next moring did the same thing and yes I'm getting a full 14V to the dist. Ok well lets try the fuel pump, new Holly mech, put this on same problems in moring again. And also new fuel filter, also checked fuel pressure and 7psi, I'm really confused, so swaped alternator from my Nova, and still doing samething. I'v tried looking for vacum leaks but by the time it starts running bad, it starts warming up and starts running better again. What do you guys think, I'M NOT CRAZY! At least not yet. Again the weird thing is that It only happens in the morning when its cold out side and not in the afternoon after it warms up out side. Also, If this helps, it has a Weiand spredbore alum manifold, with an 4 hole adaptor plate. please give this old dud some help. Sorry for the long post.
Thanks one low 69