Well, try picking the GT up and shaking it up & down or back & forth, and see if you can hear a clicking coming from the clutch bell. The stock shoes will knock against the bell when you shake the truck, since nothing's holding them in place. You could also try taking the e-clip off of the clutch nut and see if you can slide the CB out enough to get a peek inside at the shoes (don't lose those spacers though!), the stock ones look like these: http://www2.towerhobbies.com/cgi-bin...?&I=LX3370&P=7

Otherwise you'd have to take the engine out to get the CB completely off.

Or, of course, you could always try contacting the guy you bought it from and seeing if he can tell you.