[bilfman]

Definitely sounds fuel delivery related. On older trucks peeps have been known to put several fuel filters in the system. Follow your fuel lines from the tank to carb and find every filter, replace them all. I had one dual tank truck that had 4 filters on it. 2 just out of the tanks, 1 about 2 feet from the carb and the one in the carb, don't forget the fuel filter mounted inside the carb. There is a little cartridge style one in there too, it is right where the fuel line enters the carb. You can just leave this one out if you have inline filters