Hi all I picked up a 261 engine that has me flustered. The casting number is "3769925" which should be a '58-'62 261 block. The casting date is "A 5 6" which should be Jan. 5, 1956. The serial number suffix is F 255N Which I think means 2nd series 1955 The dowel pin is present for the optional full-flow filter along with the 1/2" ports next to the smaller bypass ports.
So, just what the heck do I have here...? Nothing seems to match up!
I don't know what to say about the casting number... the date code and engine serial number would be consistent with a very late '55 2nd series truck or a '55 engine sn in a '56. The dowel appears to be in the position that does not support full flow filtering, which would be consistent with the practice at the earlier '56 casting date. At least you know it's a 261!
Very strange combo. Clearly a 1958-63 engine by looking at the side mount provision. What also has me stumped is the throttle pivot position. It appears to be way to far back on the block. Here are a couple of pictures of the pivot positions used up to 1959. 1960-62 dropped the front pivot option.
I have one also that posted on here last fall trying to figure it out . Same block # with date code L 21 5 ( Dec, 21, 1955). Has 3 different mounting options. Front timing cover support like our old trucks use, side mounts and the angle front side mounts like used on Canadian Pontiac cars. Had no oil filter on it. I did drive the dowel pin in and installed a full flow filter. works great. Also has the two different throttle mount positions.
That could be a possibility Tim. If that is true, they sure did an excellent job of recreating the original look of the stamping next to the distributor.
You have seen MANY more original stampings than most of us.
How many different styles/shapes/sizes of original stampings have you seen? On the 10 engines that I have worked on, there were very different styles/sizes/neatnesses of those stampings.
I think the ones stamped on a Friday afternoons were the most interesting?
I bought two 56 3100 pickups that were used on Carswell AFB in Ft Worth and both were 235's with full flow filters. The steel filter canisters were the longer ones first used on early V8's. Could you have a military issue block with pipe plugs in the full flow positions? Probably not but just a thought.
Another example… 1954 235 full pressure passenger engine with std trans, SN xF54Z, now in a '53 with PG. The head is casting # 3837161. It's a bit of a "mystery" head, and doesn't show up in the databases I've searched. It's not uncommon, either, since there are numerous posts by people trying to ID the head, on various forums. One suggestion was that it may be a Canadian head? IDK.
TC, yes the second photo IS the head casting number...sorry for the strange photo angle, but it's above the exhaust port, just like the photo in your referenced link if you scroll down to photo 5. Not sure why you think it's not.
Tim, no worries... if you take a look at my first post, that's exactly what I was getting at. The head casting # 3837161 is a bit of a mysterious one. There are quite a few posts in the various forums asking about it, so it's not terribly uncommon. But none of the usual resources list that head. One of the forums suggested it may be a Canadian head, but I don't know that for fact.
The head appears to be related to the common '54-'55 casting # 3835913 head, since the numbers on the passenger side of the head show "913" among others (see photo), but any specific relationship to the 913 head would also be a guess on my part.
Back to the intent of my original post, while the block I have is a typical '54 235, the head is one that I'm hoping someone can shed light on, out of curiosity.
Has the separate thread been started to show stamped engine SNs and such, as was suggested?
