dragging a parachute

[XL Ed]

If you want to play with the ratios why not just limit your tranny to one gear below OD. Essentially that is all your doing by changing the rear gear. My ecodiesel used to gett better mileage pulling in 7th and staying there then using top gear (OD) and having it down shift when presented with increased load.

[bustert]

that is basically what it does on its own. it will pull the snot out of it without the OD. the 4l60 only has 1-2-3-OD. converter lock up pretty much stays the same unless pulling grade.
just needing a slight edge to keep it in OD especially flatland, it is to be expected to downshift in diff situations. on my 1 ton i had a doug nash aux tranny mainly because it had the thd 400 with no OD. beautiful truck, biggest default is the brakes were shinola and fuel mileage pretty much stayed the same loaded or not. the wife didn't like climbing into it so she got me the one i have now, great brakes, power and milage up to 24 hwy the one ton best was 16 with zero town mixed in, but basically was 10 all around.

[XL Ed]

Well here's hoping you find the sweet spot!

We presently have a 1 ton Ram dually with the Cummins miter in it. Best truck we have ever had. Never notice the trailer on with 3 horses, full of hay, lumber run, whatever we throw at it. Yet civilized enough we can run down the highway at 75 mph and quiet as a church mouse. Turning 1200 at 60 on the highway. Mileage is the same loaded or not. I have the same problem as your wife though. Bitch of a time getting in it. But I'm 5' 3" and my wife is 6' and she drives it more than me.
I bought a Jeep Gladiator for myself last year and as much as I love it I have the same problem as you when I put the 12' enclosed trailer on. Mileage in the crapper. Pulls it ok but always searching for the right gear.

[wrkdWS6]

Interested in seeing if the programmer ends up helping you out. If it alters transmission patterns to hold gears longer, change the kick downs, option to change converter lock up mph, etc. etc. I imagine it will help.

I've got a 2012 Sierra with a 6.2/6-speed/3.42 and the thing gear hunted like crazy when stock. My Dad's 2006 Silverado with 5.3/4-speed/3.42 was much better from that standpoint. The newer 6/8/10-speeds feel wacky as hell until tuned.

Shortly after I bought my truck I got engine and transmission tunes from Black Bear Performance, one of the go to outfits for GM trucks, and it turned it into a whole new truck. Not much from the power department but a considerable difference in drivability, enjoyment, just way better transmission tuning. Hauls wonderful, zero gear hunting. A handheld tuner won't be the same but I have to imagine that it will help.

Edit: One of the other big name/reputable GM truck tuners is DiabLew. He provides custom tunes utilizing the Diablosport unit. You essentially send him datalogs of the truck, mod list, desires, etc. and he puts together a tune for it. If you're not happy with how the standard handheld works out it's an option to look into.

[Iron Mike]

Does any vehicle manufacturer manufacture anything that functions properly for its intended purpose without having to throw a bunch of aftermarket doodads at it????

[bustert]

not really mr. mike
when i started in the oilfield, the equipment was built for OVER_KILL and we never had issues with the old iron. jump ahead, the newer equipment is "ENGINEERED" and it will do as built but NO loading it beyond that or it will fail.
for ex: on the blue water 2, we had gardner denver anchor winches and i could pull a fully powered up anchor handler boat back wards. on the blue water 4, we had skagget/bendix winches and we had to put fire hoses on the brake drums just trying to control payout of the 2" anchor chain.
do not get me started on the draw works, same deal just abouts.