When blocking the EGR do you need new gaskets for the 2 plates on the intake? Or can you just pull off the old gaskets and use soem RTV? What RTV would you reccomend (black or copper)?

 

The black should work fine. I wouldn't bother with the OEM gaskets.

 

I used copper on mine.
I had an EGR blockoff plate that I bought from GM but then I ran into the OTHER hole in the manifold so I got some hi temp gasket material and took the metal hose out of its bracket, cut me a gasket and used the bracket and my gasket as my blockoff.

 

I didn't see anything wrong with using the stock gasket unless it is damaged.

JeffA