27-02-2013, 09:07 AM
Theoretically there's no difference, the stroke is the same on an XUD7 as an XUD9, just the bore thats different... So basically the 9 block and pistons have to go together, I don't think you can use an xud9 head on an xud7 as the valves might not clear but don't quote me on that... Everything else is interchangeable.