Hesitation/backfire

[glock75]

Hi all i have a 95 gmc sierra 3500 4wd with a 350 in it,and went camping this weekend and on the trip up the truck was flawless. On way home today at around 2000 rpm under load it would backfire and hesitate bad and loose power were talkin 10 mph up small hills it ate on the trip up. I had to do 30 mph all the way home. It did it all the way home and when I disconnected the trailer no prob. It ran fine it was between 200 degrees and 220 degrees on the water temp.Its driving me crazy. A 2 hr trip was a 7hrs. Any ideas thanx

[gmtech121]

likely ignition. Coil wire possibly or secondary ignition

[glock75]

Thanx ill check I to it!

likely ignition. Coil wire possibly or secondary ignition