My engine is a modifed top oiler (see photo), the previous owner told me that the engine came in France, in crate, with the spare parts for Le Mans 67.
Unfortunately, I lost the photos that I made at Le Mans classic in 2022, but the description poster in front of the car in the pit was clearly mentionning the words Tunnel Ports Headers, it is why I discussed with the owner. There was 2 Mark 4 one red, one blue and both were equiped by the same engine.