Checking a few websites, Here is what I found:
On
Inliners.org show the year casting for your 261 block.
Checking this site:
http://home.kc.rr.com/mtaylorhp/casting_numbers.htm It shows that you have a 1955 235 cylinder head.
Check out my 261 page on my webshots. It shows the ports for the full flow plumbing. Given the casting number of your block, you should have the same. As a result, your splash canister will not work. I would recommend adapting a spin on style unit for optimum filtration.
I will say this, once it is done, it is one sweet ride.
