Ya it might just be easier in your case to buy a new one dual keyed already. Unless u have a machine shop nearby. Dont get me wrong I wouldn't turn away a sale lol but would like to see it work for u
So looked on innovators West website and 5.4/5.8 is the same balancer and for a dual key way u need a dual key way crank which is usually when you're motor is built u end up going that route for high power. Let me know if ur still interested