[stevef]

I just did the same clean up. On the pistons I soaked upside down in kerosene overnight. Then with a fine emery/wet &dry gently rubbed the top of the piston. I used kerosene as the lubricating media. Came out really nice.Depending of how hard the carbon is you may have to start slightly coarser. On the valves, I tried all the soaking routes, carb cleaner, coke etc. The exhaust valves put up a good fight. Ended up masking the stems with duct tape and chucking them in a drill and gently abrading until I had cleaned them up. Came out pretty good. Take care though. Could've taken them to be blasted but I operate on the premise that I will only part with any of my parts only if absolutely necessary.