Just yesterday I drilled and tapped the holes in my 1954 261 block for installing a full-flow oil filter. I followed the steps in the Inliners Tech Tips and in the Stovebolt Page, and all went well. Then, this morning I stumbled into this thread where John M. advises against using the filter on the 54 261. I do not quite see the problem. The ID of the two 3/8" NPT nipples is about 0.438", which is enough larger than the 0.366" ID passage between the oil pump and the main oil gallery. I plan on using 1/2" braided hose for the filter connection. My Crane handbook indicates that there should be little, if any, additional pressure drop, other than that due to the filter and its adapter, which is there for all 261 installations. I am using a GMC oil pump, so I should have plenty of oil pressure and flow. Am I missing something?
At least I think that I have a 1954 block. That is what I was told it was when I bought it in 1958. However, there seems to be some confusion on the casting numbers. It is a 3733950 casting. Some of the casting number links indicate a 1954-1955 block, but there is one link in the Inliners page that says 1955-1957 for the 3733950. Any insight?
By the way, the tapping for the 3/8" NPT threads went a lot better when I used a tapered reamer on the 27/64" drilled holes before tapping. The Stovebolt page said to use a 9/16" tap drill, and I could not get my tap started.
This engine has sat since 1962, but it has been great to get back int the six cylinder business. These Inliners posts and threads have been been a a great help.
Hoyt, II # 922
