For now, I am running the ERBE. I have lots of diff parts for it
With a pair of 5800 mah 3S lipos and the LST wheels and tires, the truck weighs close to 14 pounds. It weighs a little less with the Proline 40 series Mashers but not much. I use the Hot Racing heavy duty double slipper and if I give it 1/8 of a turn more, the truck won't even move

I ordered some new parts for the LST diff. When they get here, I will sit down and take out the rear end. I will take it all apart and clean and inspect every part, replace all the bearings, put two new CVDs, put a brand new complete diff in and then I'll see what happens. I'll probably take the whole truck apart and overall everything while I'm at it.