Unfortunately, your truggy has a 43/13 diff:
From the parts listing on page 29:
40516 STEEL SMALL BEVEL GEAR 13T 14.95
40517 STEEL BEVEL GEAR 43T 38.95
Link for the manual:
http://www.ofna.com/pdf/34963-x1crt-pro.pdf
Edit- skellyo beat me to it.
You'll eed the 44mm. And yes, you can gear it accordingly.