I dropped the pan on a 216 to see how the oil pickup screen was mounted. The 216 main bearing cap where the oil pickup screen mounts is much different than the 235 pictured above. I measured the threaded hole in #3 main bearing cap on my 1961 235. I turns out it is not the 1/8" NPT I thought but it is a 3/8"-24. From Mike's and Dave's responses and pictures, I'm convinced the threaded hole in #3 main bearing cap on my 1961 235 is not used. I thank you both for your kind and informative responses.
Bob
