like the title states, has anyone figured a way to convert from a 4L60 to the 6L80 out of the nnbs, I have a 02 1500 with a LQ9 swap and I know a lot of swaps have been done to a 4L80, but with having a 6.2/6L80 NHT truck, I loved how well the 6-spd worked with everything from towing and just was a custom tune away from having great shifts, or would you guys preferably recommend just swapping to a 4L80 when it finally lets go.

 

Speartech had a thread on a 6l80 swap into an nbs.
iirc I saw it on ls1truck

 

Put in a 4L80 call it a day. If I could have one in my truck I'd take this 6 speed pos and pitch it as far as I could throw it. It's just too damm many useless gears and for all the tuning on earth I still can't make it act like I want it to simply because of the way it is designed. I put 4:56's to make the truck driveable and 5 and 6th gear actually usable without lugging the **** out of it as it was from gm.

It is my understanding that you have to convert your truck to a 58X crank and 4X cam reluctor wheels in order to run the newer pcm that is capable of handling the 6L80 tcm communication protocol. It cannot be controlled with the existing pcm system in your truck.

 

Speartech did a full power/drivetrain swap. What you want is a system that will allow you to keep your long block in the truck.

Hardest and most expensive is getting your engine up to 58x DBW specs. Having done the conversion on my two Trailblazers (and sold/assisted kits with everything from custom SEMA rod to S/C 5.3L Avalance to stroker TBSS) you'll absolutely LOVE it. But it ain't cheap. As 01WS6/tamu eluded to, it's not a back yard project if you don't know what you're doing... I personally spent well over 2 years to get my TBSS tuned JUST the way I want it. Oddly, my 5.3L needed very little tuning. But having done so, now it's easy. Sooner or later I plan to get a kit to put it behind SBC Gen I/II and the BOP engines...but one step at a time.

Because I've got so much interest in it of late I've actually just started looking at a cheap GMT800 cable throttle body truck to convert so that I can start with the most complicated Gen III set up. We've already designed and outlined the major components necessary to take any Gen III 24x motor to 6L80/90 compatible. Unlike most people, until I test or thoroughly research it first hand I never think about selling, praising, or bad mouthing anything.

If I can strike a good deal on this truck, then it'll be an immediate green light. We'll become a sponsor so that we can keep everyone abreast of the progress.

 

If you have EFILive and want, shoot me a PM with your TCM tune and I'll take a look at it for you. Lower gears (higher numerical) require an aggressive calibration change to shift patterns bc the engine/trans are spinning too quickly.

 

I'm interested in this swap also. I'd love to see 20mpg out of my cammed sierra denali.