slant runs crappy when cold...

I have the same exact problem on my 63 Valiant /6. Went so far as to buy new carb, change the plugs, points, condenser, new distributor and wires and new timing chain, new fuel pump and filter. Still does the same thing! Usually in the colder weather. On the open highway when it is warmed up, it goes like a 'bat out of hell!' Can't figure it out.