im still not positive, i was pressurizing the system so i did billet injector hold downs, studded it while i was there and it quit pressurizing the system and then the waterpump died.
i just got the C's since it seemed to be the general concenses, when running an aftermarket turbo.
there are tabs on the gaskets that tell you what grade they are....I would just replace them with the ones you allready have
Sometimes GM has a grade c on one side and B on the other....As soon as you find out,Order the gaskets. There is issues with GM and head gaskets right now IIRC
I have not listed everything that I can get from GM.would take alot of time lol,If Gm makes it I can get it anything aslong as Gm has not did away with it.with all parts from Gm it takes about 2 to 4 days for parts since the dealer do not stock most of these itemes.