1984 Toyota Pickup truck will stutter at below 60 mph

Engine Mechanical problem
1984 Toyota Pickup 4 cyl Two Wheel Drive Manual

When I got on the interstate and tried to accelerate my truck started to sputter. At work on of the mechanics changed the fuel filter for me. He said that it was very dirty. When he tested it, it still sputtered until he got it at about 60 mph. On the way home it did the same with me. When I checked the carburetor and pulled the throttle linkage back I could not see and gas come into the carburetor.