I have a 09 5.7 hemi 1500 with a 6" lift and 35s I'm looking to put a 3" body lift and 37s what size gears do you suggest? The gears I have now are stock and I have no idea how to tell what size they are now. Also I installed a superchip cortex programmer in it, the thing is how vital is it to update your programmer? Here recently after I lifted it and programmed it the truck has issues figuring out when to shift, it doesn't shift hard just kinda hesitant. I had the transmission flushed but I don't think it's a mechanical issue but maybe a sensor or my chip not being updated. Please let me know what y'all think the help would be nice.

 

I agree you should check to see if the programmer is updated. I think with the superchip you should be able to program the shift points of the trans. On the gear question-with tires that size I would recommend 4.56 gears.
Jay

 

I have 3.55 gears and 37's and diablo programmer. Truck drives fine. 85k Kms and no issues as of yet. Only a 6" lift