Hello all, I have a 6.4 with the gear head tunes, the truck also has the afe stage 2 si setup, dpf/egr delete, cac pipe, running the street tune. It's lifted with stock gears 3.73 iirc and 40 inch tires. Stock trans , stock motor etc.... Problem I have is when I tow the truck starts to buck and shudder like it's cutting in and out around 30psi or whenever it hits a hill/incline or load I am usually doing around 65-70mph and my rpms are around 1800. When this happens I have to let it down shift then it will go away and I can speed up but when it up shifts again into od and hits the same rpms and boost it does the same thing. I have zero cels no codes or anything. Truck has 44k on motor. What are your thoughts?