On a hard acceleration I get a loss of power and backfire through the tailpipe. It is freshly tuned up. At highway speeds of 70 mph the engine will start stammering and there is no acceleration beyond that.
Thoughts?
Also there are no engine codes showing up

 

Fuel Filter and Fuel Pump

 

You might run fuel injector cleaner through it also, I had a 95 1500 with a 5.9 and it needed fuel injector cleaner about every 8K and I’ve always run e10. It would start missing in overdrive and clear up after the cleaner.
good luck