how hard is it to convert a 2010-2012 automatic to the g56 manuel?

 

Some of it has to do with parts,but you'll have to change the settings in your ecu to recognise your truck doesn't hanve an auto anymore. It may be easier to just get a truck with a manual.

 

i cant find one i want, i want a 2010-2012 6 spd manual single cab long bed 2500 or 3500 no dually and with cab lights

 

It'd be easier to buy one and put lights on it. I had the same problem your having back in January when I bought my 2012. To answer your question the ECU is physically the same ,but the Auto has the TCM (built into it) to make it run code free you'd need a way to flash the manual OS into the Auto ECM (if it can be done). In some ways I wish I had gotten the auto ,but I work for a manual tranny shop so here I am (new clutch is inbound)

 

X2