Atomic, Crow Or Nizpro Valve Springs

[GreenXR6T]

So you can get thicker shims for the Nizpro springs?

Is there shims under the factory springs or do the sit on the valve seal seat?

I ask because there is no mention of them in the workshop manual, and I used some shims under my newly installed Atomic springs (was Nizpro) and after looking at the manual thought they must've been a Nizpro item? They are 1mm thick.

Thinking about it the manual is mostly for a N/A 6. Maybe the T has factory shims.