I started making 3/4" to 1-1/4" adapters after not being able to find some online. These would fit your 3/4" axle and allow you to run an 1-1/4" gokart style disk brake hub. They are 3/4" ID with 3/16" key way and have a 1-1/4" OD with 1/4" key way. They work great with the Doc Locker system if you have an axle with a full key way. Other wise if you want to run your stock axles you can buy 3/4" to 1" or 1-1/4" adapters with 1/4" key ways cut. You just have to weld them onto your current axle wherever you'd like your brake disk. I've seen them done both ways.