I would agree the topic valve recession controversial.
Google "old chevy valve recession" you will get dozens of hits with photos. Articles in several magazines and hits from sites like HAMB.
Problem is when the valve recession is present it is hard to confirm the mileage, type of use and the true root cause.
Does running the SIX at 3800-4200 rpm for three hours qualify for "hard use"?
If I had to choose additives vs hardened seats and new high quality valves and guides ........I choose the valve job done right.
Valve pic Pic 2 url="http://www.jalopyjournal.com/forum/threads/unleaded-gas-vs-non-hardened-valve-seats.827920/#post-9183072"]unleaded gas vs non hardened valve seats[/url]]Picture from JJ[/url]
Redline additive ( may not be objective as they are selling additives) http://www.mossmotors.com/forum/forums/thread/9723.aspxLike I said valve recession or excessive wear problems are real and controversial
