GMC Repair: engine missing during acceleration, fuel level sender, gas gauge

Question
When I accelerate from 60 mph to 70mph my truck begins to shake until the gear changes.  Most tell me it's a tire out of balance but I don't think so because it doesn't happen unless I am accelerating.  Also I've noticed my gas gauge is jumping just a few millimeters back and forth.  What do you think?

Answer
Hi,Kelly

On the accel problem,what year is the truck?engine size?
Does it feel like a missfire?what happens if you accel from a stop does it feel like the same?
On the fuel gauge problem,it sounds like you have a failed fuel lever sender located in the fuel tank,this is a common problem,and you would need to change the fuel level sender.

ED