does anyone know what the thread is on the xu head bolts? probley should mention they are the torx type bolts.
also what sort of preparation should the tapped holes in the block be given, if any, to prepare for clamping down a refurbed head?
on cast iron blocks i have always tried to run a tap down the holes just to clean them out, not sure if this is a good idea with alloy? would need a pretty long tap!