personally i use the stock chassis but the carbon reinforced is i guess better. id personally stay away from the exoteck stuff..it usually just open a can o' worms. thats my opinion. ive never had good luck with their stuff..ive always had to elongate holes, trim extra materials off..an such. unless your running more then 13.5 on a tight carpet track with higher bite id say save the $$ and use the stock one. good luck tho!! TAMIYA FTW!!