[bigblockv6]

I checked out the auction on those exhaust valves, they are the stock hollow stem sodium filled valves, definitely a weak link as they can snap for over revving. I bought some Cat valves a while back that are the same diameter but with smaller diameter solid stems, only issue is the stems are shorter so I don't think they can be used. I intend to replace the hollow stem valves on my 478M in the future, knowing myself being a lead foot. and the fact my 478M was built up to rev over stock specs!