i dont know what your truck is using for a spur but i run the kyosho 44 or 46 tooth nylon spurs
http://www.rc-monster.com/gears.php?pg=3 and if for some reason something happens the spur would give before the pinion would. so in the long run it would be a better choice based on price. my truck came with a 53 tooth spur and i run the 46 tooth and gear it to the speed i want to get.