question about high octane gas

[jjm400ex]

i heard that high octane gas contians alot of lead. is the lead bad for the valves. will it cause carbon build on the valves or pistons/??

[bradrenea]

Some is leaded, some is "low lead" and some has no lead(unleaded).
I have always been told that the lead actually acts as a lubricant. Back when they made the switch from leaded gas to unleaded, cars had to be fitted with hardened valve seats because of the fact that the unleaded fuel did not lubricate the valve seats like the leaded fuel had, and they would wear out quickly.
As far as carbon build up, I just tore down the motor in my camaro that had been running on leaded gas for fifteen years. There was almost no carbon build up at all.