These came from an engine that was in boat in the 70's - the engine was removed after only a few days of use and replaced with something apparently less powerful. I purchased the engine after 45 years of storage thinking it was a 2.6 liter since the engine had 2600cc heads - I was correct on the heads being 2600cc variants, but the Cologne engine is actually a 2.0L V6, which I had never seen before.