Vapor lock up? Running bad when warm.

[Asahi123]

I have a 71 chevy 350. I have already changed the fuel pump. When the truck warms up it runs ruff up to about 30mph and then after that it runs good. Also runs great when it is cold until it gets to operating tempurater. I thought was the fuel pump changed it out. I have one of those filters you can take the filter out and clean. I have done that and replaced all rubbers hose for the fuel lines and have blown them out. I check the sending unit it looks good. When the problem starts I have tried to remove the gas gap no change. I have the origanal intake with a aluminum spacer and an edelbrock carb. So does this sound like vapor lock? I put the carb on last winter never had a problem with it sense now. It has been getting in the upper 90. So the problem didn't start until the temp started going up. Coolant temp fine. Should I put one of those plastic spacer between the intake and the alunimum spacer? Any help would be greatly appreciated.