[frnkeore]

The Ford factory spec for the 21 stud engines cylinder wall OD, is 3.380, that only leaves .095 wall thickness, at best (no core shift or corrosion).

Once I obtain the Ford drawings, I decided that the most I should bore my '37 block, was .080 and not the 239 size, I had intended. 3.188 bore doesn't leave much sealing area at the bottom stud, either.