I have an 86 Silverado with a 305. About a year ago, I was having problems whereby the truck would stall while driving and then not restart until some time later. This was after I replaced the fuel pump some months earlier as I recall. I took it in for repair and the shop send the carb out for a rebuild. It seemed to run better, but it still wasn't running right. It would still stall on occasion, but it would also jerk/stutter when it reached 45-50 mph or so, until you either let off the gas, or powered through. So, I finally took it to another garage a week or two ago, and they stated that they still thought it was a carb problem. So, they rebuilt it a second time (not sure if it's actually the carb I had rebuilt the first time, it could be that the first carb rebuild was a separate unit and they just kept the core). Unfortunately, it's still not working correctly according to the garage. They say sometimes it will run fine, but other times, it won't. It seems to alternate between running too rich, or starving for fuel. Now this garage is telling me that maybe the carb is just bad despite the rebuilds. Suggesting maybe I just need to buy a new carb. Now, I don't mind buying a new carb at this point, but I want to make sure that's the problem. What else could be contributing to this problem other than the carb? Would a faulty fuel pump or sending unit cause those types or problems. I'm completely naive to it as you can tell, so I don't want to shell out for a new carb and then not fix the problem. Suggestions? Also, if I do have to replace the carb, any suggestions on what type/model of carb I should look in to. Not looking for any high performance carb or anything, just something that will make the truck run right again.