How much TM should i have removed?

[Prank111]

i'm about to order from nelson, i just wanted ya'lls opinion. the 4l60 is stock (i think), i'm second owner of the truck and i knew the ex owner used to tow rv's with it. so i think my transmission has been rebuilt. so i wanna squeeze more mpg and power out of a 4.8. How much should i remove?

also can the Tow/Haul button be used for performance reasons?

[PitchBlackC3]

Ask the tuner for his recommendation. The tow/haul can only affect transmission settings, so in that regard, yes.