On my current nitro revo setup (OS .18 TZ), I'm running a 3-shoe clutch setup using the following:
Savage flywheel
Traxxas collet
Kyosho narrow CB
Mugen clutch shoes and springs
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)