Id stick some itr valve springs in there with new stock retainers and a good three angle valve job. I'd try to stay with the oem valves which will hold up to 400whp as long as nothing horrible happens with the tuning. If you plan to also add nitrous for whatever reason then I'd consider some SS valves but they are softer than oem and will have a tendancy to mushroom at at the valve tip. Skunk2 valves are notorious for this and I've seen it with my own eyes on a head I was rebuilding for a customer. The valve springs and valves themselves ahad to be cut from the head. I believe Ferrea and maybe even some versions of Supertechs valves have a nitrided tip to prevent this from happening.