I have noticed recently that when I reach higher RPM( around 2000) that the engine seems to spit and sputter almost like its not receiving fuel. The vane transfer pump was replaced 20,000 miles ago(my 3rd one thanks to a faulty fuel float assembly). The truck starts fine runs fine below 2000rpm but when you punch the throttle it spits and sputters. Also at any speed if you swerve to the left it bogs down and comes right back. However nothing happens if you swerve right. Any help would be greatly appreciated!

 

Got a fuel pressure gauge?

When was the last time the fuel filter was changed?
The swerving thing makes me wonder if you have a bad pick up tube. Does it do it on a full tank?

 

I don't have a fuel pressure guage. It does bog down with a full tank. I had the float pickup assembly replaced with the last LP. The gauge was reading half a tank but was bone dry. Found this out at 70mph in the middle of nowhere.