valve is aftermarket,and extra long.about 9mm longer as orginal and i use difrend kind spring.valve stem are 42/36mm,very hard stainless steel 21 4N.
Good but costly
just keep in mind that VW gasser valves wont work. period.
the gas heads have an actuall combustion chamber in the head. and the valves are recessed up into the combustion chamber. so for them to be the right length to touch the cam, they have to be shorter than a diesel valve, because we have no combustion chambers, except for our prechambers, therefor making our valves longer.
Found this site a while ago and saved it for future day dreaming.
These guys have it all.
Stainless backcut polished sodium filled etc. Super high speed.
Read and drool!
http://ferrea.com/index.php