I just bought a 1983 GMC Sierra that has a strong engine and sound transmission. The only issue I have noticed (i knew this when i bought it) is the carburetor. It has two problems so far. Main problem is when you get the truck up to around 35 -40mph and it shifts up into overdrive, when you slowly accelerate, the truck bogs down and seems like it's just sucking gas. Once you press the gas a little more it shifts down and is fine, but if you just moderately accelerate, it just chugs and bogs down. The next thing is when you just start it and let it idle, it wants to stall once the engine gets just over 100 degrees. Once you rev it a little and let it warm up it's fine, but it's that initial warming up where it wants to stall. My question is...is this an easy fix? I'm going to tune it up, but my next step would be to get a carb kit and work on the carburetor. Does anyone else have any suggestions?

 

Do the carb rebuild and see what you find. Your problem may be there.