The lock up direct drum has five frictions from factory. If using thin plates, you can go six. The snag is you HAVE to use the pump from the lock up because it's "matched" to the deeper drum. In turn, you HAVE to use the input shaft from the lock up as well. If using later non lock up direct drum, you can squeeze five frictions in, and use the regular input. Now the real snag is there are NO thin discs available. ANYWHERE.