My truck is stumbling (not an A-Body)
Yep, there is no fuel filter on the Magnum truck motors.....the only thing is the sock on the fuel pump. If you don't run a bottle of injector cleaner every so often they will gum up. Get a bottle of Lucas Injector cleaner and dump it in with a half tank of fuel and run it until it's almost empty. That's easy and cheap to do. I also Cheif's order of cleaning.....those are the most common issues with the trucks.