340 X Head Value

140k miles on my original 340 X heads unleaded gas valves never sunk? Wasn't an issue in my case. Do we have anyone reporting sunken valves with X heads, anyone?
I agree with this. My machinist told me "If you aren't hard running it daily you'll be ok without hardened seats " But you are right it seems to be an old topic not heard much of lately and its brought up here to discount the value of the X heads. They hold their value as do the j's If they aren't worth anything they'd be cheap and people would be buying them up. There isnt 1 318 guy here that would pass on a set of them if they were cheap.