Lefty 2.0 conversion from 100mm to 120mm?

I would like to convert my Lefty 2.0 on my Scalpel Si from 100mm to 120mm ...have any of you tried it?
Looking at the tech specs and diagrams it seems like I need the following:

- damper KH187 [part I on diagram]
-5mm spacer #1
-longer stanchion protector [C]
- CK3467U0055 LEFTY 32 UPPER AIR SEAL 16MM, SHAFT 55MM [J on diagram]