I've seen @IQ52 (Jim Laroy) make the comment that larger valves make more power everywhere in the RPM range. He oughtta know. lol I think the larger valves are certainly worth it, especially with a slant 6.
I am going with larger valves positivevalve seals valve guides if needed 318 springs and have already ported the head the only uncertainty left is stated in my post above.
