I recently purchased the Nitro mt racer kit from HPI and I need a little help with an engine for it. Id like to get a .18 or possibly a .21 for it. Im mostly worried about getting an engine that wont mount onto the truck, Can anyone give me some advice or fill me in on how to go about choosing an engine for this truck? Thanks

you can get a .18 in it no problem. HPI's 18ss will work in it as well as many others.

I have that truck with the 18ss, it works perfectly.

how do you like the .18ss? I am thinking about putting it in my SN Rally