Feul/petrol octane

[Boyscout]

1) Can a 998cc 1970 engine run on unleaded gosoline? No you will need an additive
2) If one does have hardend valve seates and runs it on leaded will it damage the engine? No it will not, Your 1970 engine does not have a catalytic converter that can be damaged
3) Are the additives for unleaded feul recomended? Yes. Valveguard is a good option.