Castle Neu 1520 on 6S LiPo Powered Gmaxx (Nitro Killer)
Predator with OS .21TM
Supermaxx with Mach .26
Revo with OS .18TZ
Kyosho ST-RR Conversion
Ofna CR with Tekin ESC/Motor (2)
Not so much an upgrade, but my rubbish allen keys stripped the stock set screw, which I replaced with a stainless one which stripped even faster. Shame I can only find the stainless ones over here :/