Nickel in blocks???

[bergy]

I agree - front and rear housing cores were common among several part numbers. Every time a casting was modified, a new part number was supposed to be assigned, but if the change didn't involve the front or rear casting face - the same old housing core boxes would be used. These front and rear housing cores were made on equipment that was the oldest at Tonawanda. The binder used was actually a derivative of linseed oil. The dimensional tolerance capability of these "oil sand" cores was not great, so it was gradually being phased out in favor of phenolic urethane binders. the "oil sand" front and rear housing core boxes were very old & were used for multiple part number blocks over the years.