I have a Mugen MBX5R buggy with O.S. .21 VZ-B V-Spec-T (P) engine using Mugen Clutch Bell 13T 5x10 C0719. I want to swap out the existing clutch for something better. Mostly I do bashing, but I like racing capability. For me it's just a hobby, but I tend to lean towards the upper end for equipment, within reason. The current clutches (I have 2 MBX5R buggies) is the standard Mugen clutch with the exception of aluminum shoes (3 sided) that were replaced a few years ago. I'm fully competent in engine/drivetrain mechanics and can do maintenance & repairs. I built buggies as kits from scratch. I assumed that replacing the clutch assembly would make sense since all components would be new, but if different quality shoes or springs are suggested, that's not a problem. Once I get these buggies back up to current standards I am thinking of getting a new Mugen buggy or maybe an on road car. Still undecided. Finally in the past a lot of people have suggested a BuKu Clutch assembly, but hardly anyone sells them now and an email to the company has gone unanswered so any suggestions you have are welcome.