So after I sent my pistons to venolia, they could not figure out what was wrong with them. Turns out mine were fully machined. They asked if I could makenthem a cast of the combustion chamber, which I did. They figured out what was wrong. Here, in the 90s before cnc computer machining, they used a plexiglass template. When mynpistons were made, the template was put on upside down so the lumps were correctly positioned but the shape was backwards. So in deference ton the fact that my pistons were in fact 20 years old and long out of any warranty, they worked it out with me. I paid the cost of new raw forgings, they handled the rest and made me up a brand new new set of pistons. They also machined the lumps off the original pistons for near zero deck flattops. Hats off to Tom Prock at venolia!