Vince and I were good friends years ago. I helped out around the shop for a while before working for Mercedes-Benz. Also I specifically talked with Andy back in 2012 (around there) about this engine after I saw it at the South Bend meet. All of the Due Cento engines had been stamped, this one was not. Also Andy confirmed that none of the engines had a hole in the cylinder, this one pictured above did. There was an engine for the Due Cento that was blown on the dyno, but it was numbered. Somewhere I think I have a list laying around from Andy of which blocks were R-3s, which were built to be R-4s, and what block numbers were R-5s. He did confirm that the engine above does have one of the original intake systems and pulley setups that was used on the car.