Able to tune 66RFE swapped into a 1500? Stock 5.7L/66RFE tune from a 2500?

I'm wanting to ditch my 65RFE and swap in a 66RFE in my 2014 RAM 1500 5.7L and wondering how HP Tuners would tune this. Would I be able to just select "6-speed Transmission" under the general tab of the Transmission menu and then use the stock 2500 tables for everything else, just to get it driving? Does anyone know if the shift scheduling and transmission control will work like that when using a 1500 ECU to run a 66RFE? Would I have to have a GPEC2a PCM and harnesses (abandon the idea completely) or can the 66 be run in a GPEC2 truck?



Does anyone have a stock 2500 5.7L/66RFE tune that I could look at to get an idea of what it looks like before I spend money on this? Right now I'm just trying to make sure that I can actually do this before I spend a $1000 on a transmission.



Background knowledge: The 66RFE is a gas version of the 68RFE in the 3500s and uses 68 guts in a 65 case to fit big boy trucks with gas motors. It's beefier, has better ratios, and operates as a true six speed, but the 2C and 4C apply clutches work a little differently and I'm not sure how this software can compensate for that. Both transmissions share the same valve body and solenoid block, so I have no idea what is reversing the 2C and 4C operation unless it's fluid pathways inside the transmission case or in the planet assembly. I've called eight different shops and only found one person who said they know it can be done and have seen it done. Everyone else, including the internet, thinks it's impossible and that I'm crazy.

I've never been in a 66RFE equipped vehicle, but I do know that you can tune the 65RFE to be a 'true 6spd'. It's one little switch in the tune to allow it to use the '3rd' or '2p' gear in normal automatic upshifts. Literally the only difference between the 545RFE and 65RFE is they number the gears differently.

I do know the 66RFE gearset is different and maybe that's of more interest to you, can't help in that regard.