Here's basically the first 5 things I did to mine:
1-Got a good scope mount (went with ARMS 18) and decent scope
2-Shimmed gas system at one of Hungry's clinics
3-Had spot welds broke on the flash hider at the clinic and got a flash hider with a bayonet lug (thanks Hungry

)
4-Replaced chu wood stock with USGI stock (decided on a USGI birch stock)
5-Replaced op rod guide (went with Sadlak) and the op rod spring with one for an M1A, since it wouldn't work with the Norinco one
Other than that, I've also given it the Sadlak tactical mag release latch, the QD sling mount, and a Harris bipod. I still need to get around to bedding it, maybe getting an M1 Garand rear sight, and having some other superficial tweaks done to it, but as it stands right now, she's almost where I want her.