50mm from the weld in the original pipe like everyone has said. Take your time and be careful - don't screw it up.
The link pipe supplied is for the new can only (unless you want to butcher the original even more). A reconnection sleeve can be supplied for £15 when needed. A little smear of clear silicone sealant on both ends of the link pipe prior to final fitting and tightening will ensure no leaks.
You'll LOVE it!
Garry
