Rocker cover

Any performance valves available for these heads???? Are they 5/16 stems??? or, 3/8 I have Bronze guide liners and install reamers for 5/16, but, not sure if I have them for 3/8....

Onward.....

Al(BWA)

I see these for sale on ebay all the time. Bought myself a set for when I pull the head on mine.
http://www.ebay.com/itm/225-Slant-S...eel-/391090447313?hash=item5b0ecea3d1&vxp=mtr

Mike