I rode my friends bike that was a 790 who did the big bore and I can tell you it is quite a bit of a jump in power. Especially when I went from my stock displacement with stock compression bike to his BB then back to mine. Made me want to BB mine but I don't have the cash. His still has the stock 790 cams. I didn't ask about head work either but the way he talks I think he would have mentioned it if it had been done.

I learned all I need to know about life by killing smart people and eating their brains.
Eat right ,Exercise ,Stay fit, Die Anyway!