1999 GMC C1500 Driving odd

I have a 99 GMC 2wd with 5.0 V8, when I take off from a stop at about half throttle or more the truck lunges and lugs down and starts bucking, but quits as soon as it shifts or gets a little speed. I have changed the fuel filter, added fuel system cleaner, but this did nothing. When driving around at normal speeds and flooring it or just getting on it a little it does fine, it only acts funnt when taking off from a stop.