Usually people adds weight for crawling? You'll want 60/40, more weight at the front and down in the wheels, you can wrap solder to the wheels to add low down weighs
I'm not going to be treating it like a dedicated crawler because it's really too light, small, and underpowered. The best thing to make this little truck faster is to remove weight. I've considered wrapping thick solder in a few layers inside the front beadlockers as well as a handful of ball bearings inside the tire because they're still 'fluid' and would provide a lot of front weight balance. Without the bed, and a bigger battery up front, the center of mass is about where you said; it's right around where the number stickers on the doors are.
