use the engine replacement program to get the sh.18, it will cost you alot less: http://www.redcatracing.com/itemdeta...tno=sh18engine

or for more power but more money you can get the os .18 cvrx: http://www.clermontmotorsports.com/s...lue-11j/Detail

the 2 are direct fits, i have them both, i am very happy with the sh.18 in my volcano