what would happen if i didnt add the additive a couple times and driving say 20km before i remembered.....not to say that happened

also if my head is converted, and i dont know about it, would it matter if im still adding lead to it?

p.s.

it was the highest octane fuel

The additives are not adding lead, they are lubricating the valve seats to avoid recession - achieving the same thing as lead but without actually using lead.

It does not matter if you use it if the cylinder head has been converted. Flashlube is also used on LPG cars that have hardened valve seats but require extra lubrication.

It's no problem if you forget to add some additive, especially if your putting round town. There will be some residual in the tank anyway and the valve seats do build up a 'memory' - not to the same extent as lead memory but will offer some protection if you forget to put some additive in the tank.

Driving on the highway for an extended amount of time is the worst thing for valve seat recession so always make sure you have additive in the tank it your going on a trip somewhere.

The octane level of the fuel bears no influence on valve seat recession by the way.

ok thanks for the info man