Truck idles and revs perfect but on road engine dies

[E-Rey]

I was hauling a load going down the road in 9th gear rpm @ 1,400 and engine just died. I pulled over and cranked it and it just turned for about 2 min then finally it started. It was sluggish when it started but got it to idle fine and got back on the road. I dropped my load and was going back to the yard and it did it again, in the same gear @ the same rpm. Got it to start again after a few cranks and ran fine. I checked the fuel tank and noticed a tree branch inside the tank and a bunch of trash in the tank. (someone messed with my truck and put it in there) I dropped the fuel tank cleaned it all out, blew out the lines and replaced the filters and its doing the same thing. Idles perfect, revs like a champ. It's a 10 speed so I can go through the gears 3-6 like normal but when I get to 7,8,9 gear the engine just dies and now it wont start unless I spray it with starter spray and it runs fine at a idle but as soon as I get into those higher gears it just shuts off with no warning. When it is idling I can shut it off and crank it right back up like it has no problems at all. It only has a hard time starting when it dies on me. Im starting to think its a electrical problem being that it idles and revs fine. Does anyone have an idea what this could be...? Any suggestions would be appreciated.. Truck is a 97 CH600

[farmer52]

Fuel transfer pump?

[E-Rey]

Fuel transfer pump?

I'm gonna look into that and ill post updates soon. Thanks!