Yep TFS with stock Valve's and springs they come with from there Factory. Funny you mention Ferra"s Valves !!!! The valve That broke/hit the pistion was a Ferra Valve.Had 3 replaced last year or so when My other motor Blew up.The number on the Valve was F6600 ?????? SS-I never even thought about how the exhaust valve on the TFS are in the same location as stock SHOULD NOT HAVE HIT ?????? You just gave me more to think about :cheers: :cheers: