Stainless Steel Valve question

[PA Dart Guy]

I was told by a machine shop that if I used a stainless exhaust valve that I did not need to have hardened seats installed for unleaded gas. He told me that the hardened seats only needed to be installed if I was running a stock steel valve. Is this correct? It kinda makes sense to me.

 

[lilcuda]

They are incorrect. Find another machine shop.

 

[66dartgt]

Ive always had hard exh seats installed in any engine Im building regardless of the valves being used, unless its a stocker and there are no changes to the seat size (ie 1.50 to 1.60).