here ya go
http://www.hpieurope.com/piw.php?lang=en&partNo=76937
ya need a small bushing or bearing to go in there. The wheel bearings from my crt.5 fit, I've also heard that clutchbell bearings are the right size.
It is also a little bigger, so I went up 1 tooth on my pinion to compensate. I still net a little down gearing, but that's fine by me.
edit: dunno why I was on hpieurope site...thought it looked funny.