Hi Izzy,

they should just be standard machine bolts or even course thread, take the header to a nut'n bolt place and they can size it for you if you cannot get to a store, someone should be able to tell you what size the bots are. I also had to add a spacer to get my AX 46 to fit my Tiger, but only needed a 1/8" spacer so the stock bolts worked fine for me.

Calvi