Weight is not good for 60e. Built408, how long u been running w/above mentioned unit. How hard do you drive it on the street? I took an 89 RCLB, put in modded ImpySS LT1. Left in bone stock 700r4( 1 wk.). I know I said STOCK. Had built 60e(2 wks. sun gear, planetary broke off 5pcs.); same guy did but w/ upgraded planetary & 1 other upgrade...sun prolly. Built 60e #2 snapped input, destroyed 1 wk shy of a year. Said he wouldn't cover. It upshifted extremely hard(chirped em). But I should say my rearend blew & took trans. too. Soooo...prolly rear did most carnage, that time. Best guess on weight 4700#. Still can't afford to fix.
On the 04, I'll give FLT 1 shot at a 4l6xE. I plan on more power than older truck. If a built Level 5 goes, 4l80e will be the end all be all.

BlackSSS, I know blown trans.(s) gets $$$, particularly, if bought more than once. How hard do u beat on yours on street? I might forego FLT 65e, & go bite bullet for 80e. I usually go overkill for pc. of mind.

 

hey, no problem....ill get it and send it to ya

 

I feel that about 500-550 rwhp is about where the 4l6X will work for you guys. Weight and torque are a major roll for the survival of this trans. I have many transmissions exceeding those #'s and those guy's were told up front that I will build it, but this is what can happen.And yes 700+ rwhp is a pipe dream and an advertising effort. I would rather not sell a trans then to do something that I know damn well will explode shortly after it is installed. It for me is not just to get the sale. It is about giving you what you deserve and what is right for your application. We are working on some new parts for these units to push that 600rwhp mark. But like anything else it comes with a price. As far as a trade in on the two units, I would recommend you selling the 60 and then purchasing the 80. We do not do upgrade specials on the two different units. Vince

 

I beat the **** out of it DAILY However, wasn't really beating it on this failure

 

heres the trans table graph requested.

 

I second the opinion on calling FLT. I produce similar numbers as you in the same platform (AWD SSS) and my FLT LV 65E did just fine. Cutting 1.61 60 ft times in a 5500 pound truck surely challenges the build quality of their work. There is obviously a limit to what the 65 E can effectively handle and alot comes down to daily driving habits, temperature and tune as eluded to in the aforementioned posts. Good luck with whatever route you take.