1 barrel rochester carb 1967 problem

[Ozzy2013]

Hey guys need a little help its cold here 15-25 degrees. I rebuilt this carb checked the timing ,points etc .The fuel pump is good the truck cranks for a long time before starting .If you use the choke or pump the petal it seems to make it worse.. After it starts and warms up it runs great and starts easy. The compression is good also its a 250 6 cyl didn't find any vacuum leaks either. It is a 1967 Rochester b carb do they have inherent problems? Thanks figured I would ask im sure some of you have ran into a similar problems. New brass floats and they are set properly also. Thanks Oz