No I'm not a coal roller I just wanna get all the power out of my truck I am always pulling big trailers but my truck is a 94 Chevy 3500 6.5 turbo
@Tim3596 what transmission do you have, and how big of trailers? How long of pull?
The biggest deal with keeping a 6.5L happy while towing is maintenance. cooling system is the big one that needs looked after, radiator needs to be spotless, and the fan needs to work. Never let it get above 210.
I would save your chip money for a big exhaust, and keep putting money in the bank for a big turbo.
My favorite vendor is Leroy Diesel, but other safe options are Heath, Kennedy, Lube Specialist, DSG, etc.
For a heavy puller, a Diamond Eye 4 inch exhaust, and a Fluidampr, and a special spec t-stat from LeroyDiesel.com, and a fresh fan clutch and whatever other maintenance parts you need from Rockauto.com would be my first stop.
As far as the turbo, everyone seems to love the A-Team Turbo, especially for towing. a Holset is another option, and PT wiring solutions offers a kit to install the Holset, but by the time you source all components, the bolt on A-team will likely be the cheaper option.
If my opinion matters, I will be going with an A-Team when I can hold onto the $ long enough.

But with the fleet I have, the $ seems to disappear just keeping them all maintained, let alone buying performance parts.
All of mine are for work only and tow relatively heavy, most of them only have the trailer off for an oil change or tire work, the last one was bought at 238K and I blew the motor at 269K, and there was less than 1K trailer free miles in that time frame. I haul farm equipment out west (California, Oregon, etc) so I get to pull alot of mountains.
