http://www2.towerhobbies.com/cgi-bin...&I=LXGGP8&P=ML

It says it fits the rc10gt but is it a direct fit or do I need new engine mounts?
Thanks

it should go in..... if you go to www.osengines.com it says that the new .18 cv-rx engine should just drop right into a truck that fits a 12 or 15 engine

Nice. That should drop right in. The clutch setup may require some shims, etc. but nothing else. You should really consider getting a new clutch setup if you are running a 2-shoe or a stocker. That engine makes much more torque than the RTR motor that (I am assuming) you have. Also don't forget your motorsaver filter, kepp the stock filter on the stock motor.

I am going to order a motorsaver and a mip 4n1 clutch with it. This thing is going to be a monster. Any suggestions on gearing?
Thanks for the help!

im not sure bout the gearing sorry but you could take it to the official rc10gt thread and ask them cos they all own them and or do a search