I'm in the same boat: my Vitesse was sold to me as having had a recent engine rebuild with unleaded head but I've got no way of telling.
The way I understand it is that the lead dampened the hammering the valves give the valve seats and it's the seats that are hardened on an unleaded head.
Running an original head on unleaded will cause the valves to rapidly wear out the valve seats causing a loss of compression and reduced performance. Please feel free to correct me if I'm wrong but it shouldn't lead to the valves burning out and catastrophically damaging your engine.
I'm planning to run mine as is or I might just drop one of those silver ball do-dads into the tank just to be on the safe side.
Having said that, I would be interested to know if anyone can tell us how to check to see if hardened valve seats
are fitted?
