Quick update. Ordered parts. The SIII and defender parts manual agreed on the part numbers for the valves and collets, so I was confident.
That's was...After lapping in the valves, it appears that the valves and collets are different from the older type - they have smaller collets. This means the valves sit deeper in the valve spring cup, with less spring pressure, and not enough valve top sticking out to make contact with the tappet. These later valves and collets have three grooves where they contact, whereas the older type have one. AAAAARRRRRRRGGGHHHHHHH! :violent:
New valve springs and cups ordered. Lets hope it all fits.
