999 has 5 clutches in front drum...you can put 5 clutches in the 904 drum by using the thin disc and steels...been there done mucho times.

904 drums don't explode due to there mast...or they are small.

Tony

70 AARCuda Vitamin C
71 Dart Swinger 360 10.318 @ 128.22(10-04-14 Bakersfield)
71 Demon 360 10.666 @122.41 (01-29-17 @ Las Vegas)
71 Duster 408 (10.29 @ 127.86 3/16/19 Las Vegas)