Jacob ;
First & formost , _thank_you_ for your military service ! .
The unleaded thing is a red herring , I'm running a stock 235 in commercial service (towing , hauling scrap etc.) and it's never had any valve trouble , either it will or it won't , just drive the damned thing and enjoy it !.
If the valve seats ever recess , then it is time to do a valve job with hardened seats and stainless steel valves but not before and don't worry about it .
