Im having an absent minded moment here. Seems most common diff setup for truggy are 7-10-3... Here is my question what does 7-10-5 do to the rear and what would say 7-10-2 do to the rear that 7-10-3 doesnt??

Going thick in the rear will make the rear feel more planted during cornering. The draw back to this is it will push a lot more when getting back under power comming out of the corner.