Im in the process of building a 454 street engine for my chevelle.I want to use roller rockers.ive been told I can use stock covers as long as I use two valve cover gaskets.will this work?has anyone done this?If I use the taller factory style offered by ground up will my a/c brackets work?

I do not have the factory "rear over the valve cover AC bracket". Mine never had that rear brace. I doubt it will clear a tall cover. You can run a GMPP tall cover and clear the AC box though. You may only know about the rear AC brace by trial and error though.