Hey , How ya doin? I have a lawn kart with 4 inch band brakes and I ran them for a couple years. Then I got a new engine with alot more HP and I said "man I need better brakes to a friend" mand he said no you don't just a new set of those. So I got a new drum and band and installed them and it made a world of difference. I can lock um up if I want to now and cause its a live axel both rear wheels stoping it works real good. So before you go to alot of trouble and expence try a new drum or you can use an old clutch drum if its 4 inch and put a new band on it. I think you'll be surprized