I am considering a gear change in my 16 1500 Crew Cab 2wd, with 5.7 and 65RFE trans and 15K miles, but not until quite a ways down the road. Most of the shops locally are swamped for quite a while and need a few days with the truck, which will take some planning and is down the road.

The truck currently is geared with 3.21s and 17 inch wheels, dual exhaust, and Moes 85mm TB. As typical with a 3.21 geared 5400 lb truck, it’s a bit soft off of the line, but pulls very well after 2000 rpm. So far, it has pulled my 3200 lb Duster on a 1500 lb open trailer fairly well. You just need to keep the revs up on longer grades to around 3500-4000 and lock it into 4th gear at around 60 mph. I have a Prodigy trailer brake controller on order. When not hooked up to the trailer, once above 2000 rpm, it accelerates hard after 25mph or so, roughly around 7.1-7.2 second 0-60 shown on my Gtec pro.

Until I get around to a gear change, which is not urgent as mentioned, would adding a Diablo unlocked PCM and tuner help offset the slightly soft bottom end performance in the meantime, or should I just leave it alone? On my next set of tires in a few months, I will be bumping up from 265/70/17 to BFG K02 or General Grabber 285/70/17s to fill the wheel well in a bit more (have 1.5” level on front), although I doubt that tire size increase will hinder performance notably.

 

There's a bunch of torque mgmt in this model. Especially around the throttle. Getting the tuner on there and removing those throttle restrictions will give you a good bit more low/mid rpm power