I know you gotta shim the VG with a Vspec head, do you gotta shim it for 30% out of the box, it didnt come with a shim so I assumed it was okay...Input?

I'm getting a new cooling head for this thing, I get it ripping last night with good smoke and it ends up at like 290.

Also Switched from an OS8 to an MC9 and it seems to run a little better. Opinions? (Was looking around, turns out MC9 isnt the right plug...Just one I had in my box)

I'm just starting to get more used to engine stuff, so I still ask for opinions anyway.