Re: 6.0 miss fire
If the injector has been changed, and the problem is still present, i would think its something eletrical. As you increase engine rpm's the miss or stumble would become less noticeable. Any smoke or power differences? Or just the surging you were talking about?
But like Iceman said to torque converter shudder would do the same thing also
'94 F-350 4x4 DRW 5spd
Intake, DP, IDM Mod