Converting Kyosho ST-R, new to brushless conversions...

[jnev]

The best set up you can run with the parts available now would probably be the Quark 125b with a Neu motor. Many people wil get a lower KV motor and then run higher voltage battery like a 5s pack. But this is your choice.

For the battery tray, you can probably use a Kyosho twin force tray, or you can always make your own. For the motor mount, the rc-monster one is the one you should use probably: http://www.rc-monster.com/proddetail...rcmkyoshomount

You will want to use the Kyosho mod1 spur like you said and a mod1 pinion gear as well.