So I am about done porting out my head and I'd like to know if there is performance STOCK sized valves and valve springs available. I'd like nitrate filled valves and I'd also like to do bronze valve guides.. can someone please link me some valves ? I'd be interested in performance , stock and also budget ones like ebay or something.. I'm having trouble finding them so please help me by posting some links for me.also I found bronze valve guides BUT I can only find 6mm ones. Are the 6mm guides for stock size valves ?reason I wanna stay stock size valves is comparison reasons mainly. I'm actually porting EVERYTHING. Header flange , sc horns , intake Manifold , larger tbody and even ported the sc.. I plan on running a 19% pulley on the stock factory sc and a ns2 cam so I need to open up the intake accordingly.