Flat-tops for pistons, but the head is milled, although I do not know precisely how much, as the PO had some work done in the 80's. What I do know is that when looking at the combustion-chamber face of the head, held up next to a "hot" performance head, I have more of a "street" performance head.

I turned down the idle, and viola, no dieseling. The only thing is she lopes a bit rough for my taste, so turning down the idle required some more fiddling with the carbs. This is made more difficult by the fact that she's not breathing as well as she should, as I've not yet installed the new exhaust system. Next stop...