I cant see that trans lasting long behind that heavy truck with larger tires and a trans brake.
if you gear properly then the first gear of the 80E isn't bad at all.
it actually made my truck quicker I think. once you hit second you will be glad you swapped to a 80e. the drop between the 1-2 shift is night and day over the 60E.

 

GREENSIERRA I bet the 1-2 shift lost motion is much better in the 80E than the highly modded 65E and Cir-D 3200 converter I'm running. Nature of the 80E Beast.


My goal right now, (as my once fuzzy hindsight is crystal clear now), need to use the 65E.

I've spent $2,300.00 in hi-po hard parts alone. Best of the best.


I think with normal line lock / hydro-boost street launches and letting the HD2 do it's job along with the Circle D lockup, Dearle 40K GVW w/180 thermostat and super fan cooling 3+ qt capacity pan, should live a reasonable life in my truck on a CD 278mm that stalls at 3k w/BlackBear tune I'm running.

I have both Sonnax servos installed in my trans also. Shifts are mildly "proud."

Re-geared to 4.56:1 running a 34" tire.

I've never seen trans temp go above 175 normal driving.
Towing, 185-190 pulling a 7x12 tandem with 2 hogs on @ 70+ mph.
Gauge is Auto Meter 2 5/8 mechanical reading oil temp in Dearle flow through style pan.

Tow Function Button / trans parameters were left stock in B-Bear tune per my request.

My motor upgrade I'm doing now will lay down some respectable N/A numbers at the rear wheels. 350-370 optimistically.

I really don't see where the 4L65E I've built shouldn't be up to the task. Barring any repeated 4WD launches, I feel reasonably confident about the power handling capabilities of this trans. I guess I'll find out.

Any thoughts or feedback appreciated...

 

4wd launches won't burn it up, blowing the tires off and hitting second gear instantly does more damage by trying to centrifugal apply 3rd gear.

I did a lot of awd launches when I still had a 65e that was fully built. It's how it's built, tuned and driven.

 

Agree.

 

I used to run a FLT LVL6 65E, 3600 circle d multidisc, Black Bear tune. it held up for about 40k of hard abuse with around 370rwhp. it eventually starting slipping on the 1-2 so I swapped to the 80E.
I know you are set on the 65E, just trying to help you from what I have learned from running a larger tire