The one I have listed in my post above is the one I have in my MT and I am running the HPI race clutch with the Savage vented race CB. You will need more then just hardened final gears to run this engine.

Your T 15 has this part look at the link below that has the hole for the screw you talk about and you will need to use it with the engine I listed. Your T15 DOES NOT have a pilot shaft! You might be able to use a pilot shaft engine but I do not know as I have never tried with my MT.
http://www2.towerhobbies.com/cgi-bin...?&I=LXM720&P=Z