30psi_gst

Couldnt figure out where to make this thread so ill just make it here. Ive got a 8.5:1 bottom end but my head is stock minus a set of Skunk 2 Turbo 1's. What can i rev it to safely with the stock valves and valve springs. A friend of mine has one thats all motor and he revs his to 8k. I go to at that, but is 8500 ok or is that pushing it? Also what can i rev it to with lets just say supertech duals and a supertech valves/retainers. Could i rev it to 9500?