Fuel pump is a suspect; recent-production units are cheapened in that they lack the follower spring that keeps the arm in steady contact with the cam lobe. To rule it out completely, unbolt it and pull it away from the warmed-up engine, then start it and see if the ticking's gone. A carefully-chosen older fuel pump (NOS and/or rebuildable type) is the fix.
Also make sure you're not getting misled. A single-cylinder exhaust leak (faulty gasket/cracked manifold) can sound an awful damn lot like a valve tick and drive you nuts trying to find it.