welcome to the shop Frank - if you fiddled the carb and the problem hasn't changed, have you checked everything else? like ignition resistor, and the bypassing of it when starter's engaged? is it cranking at a decent speed or slow? fuel pump supplying a good flow?
the only time I've had any problems starting w/ the rochester is when the truck sits long enuff, the carb goes dry, but full choke and lotsa pumps on the pedal always works pretty quick
Bill