When mocking up my 261 block, I noticed I had two different styles of gaskets on hand. One, typically made by Best Gasket (first image) shows some of the holes towards the front of the block covered or restricted (NOS gaskets like the Victor 3210 seem to have this same feature unless they were marked as for 1954 block); the other gasket, made by Fel Pro has provisions for all hole (as mentioned, the one I saw for a 1954 block matches this). Any reason for this discrepancy? I want to use the correct gasket but I am confused. If I had to guess, it seems after 1954, they restricted or blocked some of the holes on the front of the block to force more coolant flow to the rear of the block, and as such, I should use that one. As a note, it appears I have a 1960-1961 block based on full flow oil provisions as well as casting number. Any help would be appreciated.
I've only had one 261 and that was nearly 60 years ago. We also discovered what we thought was a 235 in my friends '57 pickup was a 261. Try to do some searches here. I think I remember a discussion about 261 heads, gaskets, and extra holes some time back. Maybe Stock 49 can help.
"I wonder if God created man because he was disappointed in the monkey?" Mark Twain
The 261 block and head has additional water passages between the cylinders that the other Stovebolt engines do not have. So, yes the 261 head gasket is specific to the 261 alone, and shouldn't be interchanged with any other application Stovebolt head gasket...
CNC-Dude, I'm well aware of the "steam holes" between the siamesed bores as one among a few defining features of a 261 engine. As my original post states, there is a noticeable difference two different 261 head gaskets, one typically made by Fel-Pro and one made Best. If you review the attached images in the post (one displays, the other seems you have to click on to load) you will see the difference I mention. Basically the Best Gasket covers some of the holes on the front side of the engine while the Fel-Pro one does not. Again, the only thing I can seem to guess is the Fel-Pro one may be based on the gasket used in 1954 (I base this on finding a few NOS 261 gaskets listed as 1954 only), when the 261 was introduced, but they adjusted the gasket from 1955/1956 onward maybe on account of some minor heating issues at the rear of the block. My question was, if my assumption is right as I can't see any literature or discussion on this topic.
