My Blur XCc fits perfect, I want a 29 hard tail and was looking at the highball. The thing I can't figure out is how I can possibly make the highball fit when the stack is almost 3" higher. On the Blur I've only got a 10mm spacer and 100mm +6deg stem. I also have riser bars on the blur, but that's only +20mm.

Blur XCc (XL)
Reach - 18.1"
Stack - 22.5"

Highball C (XL)
Reach 17.3"
Stack - 25.3"

Am I missing something? Maybe I'm misunderstanding reach/stack.