I just got this engine from my father that was supposed to be a 292.
He supposedly bought it new from a dealer in the early 60s.
After removing the head and freeing up the pistons I find that the cylinder size doesn't match what a 292 would be.
I suspect it is a 270ci engine.
From my research, the 270ci engine is the same block as the 292.
The bore is 3.75" and the stroke is 4".
I haven't dug any further into this engine yet.
I will need a complete gasket set for it to reseal after checking it out.
I suspect that the gasket set is the same as the 292.... I hope.
I just don't want to be stuck with some weird octopus that I cant get parts for.
I found the casting # just above the starter and it reads "CON3 J95"
The stamped number next to the distributer is "S1028XJ"
The 2 may be a 8 or not there at all.
It is BARELY visible and just like scratched in the iron.
Hopefully someone can help me ID this engine.

Also I am looking for a adapter plate so that I can mount the starter after I put a automatic on this engine.
The starter mounts in the bell housing now.
Does the 265-350AT starter adapter that Wilcap makes work for my engine.... once I find out what I have.

Thanks for all your help!

I forgot to add that the rocker arm cover is rectangular and has no curves in the sides like the 250 has.

The 7 main bearing modern in-line 6 cyl. did not come in a 270 CI version. Would be a 230-250 or 292. They all looked the same except the 292 block was taller. The push rod cover was about 4 5/32" tall on the smaller engines and about 2" taller on the 292. The 7 MB engines had the distributor mount more to the front of the engine block and had a full flow oil filter mounted next to it. The entire family used the same looking rocker are cover gasket.
GMC had a 270 CI engine but it was an old design and had 4 main bearings. It was 3 25/32 x 4"...The rocker cover was held down by two center studs/nuts.

The dimensions you give would figure out to about 265 cubic inches.
Mike

This engine had no oil filter originally... that was added with lines coming from the oil passages.
The Rocker cover has 4 screws around the edge of it where the gasket is.
I'll have to check, but I think the distributer is in the center.
The engine mounts under the front pulley and on each side of the bell housing.

Is there a way I can post photos of it here?

Can you locate a date code on the engine? It will be a letter and 2 to 4 numbers.

I would safely say that the engine is no newer than 1962. The 292 was first out in '63.

A date code sure would solve it tho.

The engine code could also tell us something, but I believe the books I have don't go that far back.

There is a 950 on the driver side of the block if that will help with finding the build date.

I would also say that it is a 265ci engine.
Where would I find a gasket set for this engine?
I will be trying NAPA tomorrow.

I will have to look up torque specs for this engine now.

Thanks for your help so far..

The description you give of your engine leads me to believe it is a 261 truck engine. They look much like a 235. Four bolt valve cover, no oil filter, front mounting would make it a truck engine....My two cents worth.
Mike

From the info you have given I would guess its a 261 Chevrolet truck engine.It had a 3 3/4" bore and 3 15/16 stroke. Was an enlarged version og the 235. The head gasket is different from a 235. The valve cover will be held down by 4 screws -on the outter edges. If its a 1954/early 1955 the the water pump will bolt on to the front of the block and there will be two large "water holes" behind it. The 1955-62 version has a large opening in the front of the block, the outside of the cylinder barrel can be seen and the water pump impeller fits into the opening. It will use a different oil pan gasket than the 1954 but most other gaskets will be the same. The later versionshad a full flow oil filter but it wasn't built into the block. It will have cast rocker arms and a rocker arm shaft(s)...the 7 main brg. engine had stamped rocker arms and no shafts.

Here are some URLs of my engine photos.

http://home.insightbb.com/~galactica5/auction_pics/P9170005.JPG
http://home.insightbb.com/~galactica5/auction_pics/P9170006.JPG
http://home.insightbb.com/~galactica5/auction_pics/P9170007.JPG
http://home.insightbb.com/~galactica5/auction_pics/P9170008.JPG

Maybe this will be helpful.

I agree with chev nut, it seems to be a 261 from what everybody tells me.
It has cast rocker arms but when dad bought this new as a crate engine, they claimed that it had "extra mains".
What do you mean by "no shafts"?
This rocker arm shaft is 2 pieces on this engine.

No shafts means that the rockers are like those on a Chevy V/8 engine each rocker is on it's own seperate stud and has a nut holding the stamped sheet metal rocker.

I found a site that says that the casting #"CON3 J95" is a engine cast in 10/09/1965.....
Is this a good guess or am I wrong?
Or is it 10/09/1950?
Did they make a 261 in 1950?

no 261 in 1950. There should be a block casting number located above the pan flange on the passanger side of the block it should be one of these numbers:
261 cu in year engine block block casting numbers

54-55 FIRST SERIES 3702436
54-55 Chev Trk 3703414
55-57 3733950
55-57 Chev Trk 3836340
55-57 Chev Trk 3733340
55-59 Chev Trk 3837012
56 3738813
57 3836340
58-62 Chev Trk 3836340
59 3739365
59-62 Chev Trk 3769717
59-62 Chev Trk 3769925
60-62 3769923

If it is a 261.

Canadian Chevrolet passanger cars and possible some Pontiac passanger cars were supplied with Canadian cast 261 engines, I don't have access to those numbers.

Its a 1954 engine....note water pump extends above block. If the bore is 3 9/16" its a 235.
If the bore is 3 3/4" its a 261.
It will not have "extra mains"
End of story

When you said where the number was I checked there and I found it!
Buried under 1/4" of grease 3733950.
So it IS a 55-57 261.
But not 7 mains?..... you certain?
I was hoping the guy who sold this to dad wasn't bulls***ting him.
But is seems that he may have.
I haven't pulled the pan due to needing a hoist to get it on my stand.
When I get that open, then we'll know. LOL

Thanks VERY much for your timely help on this mystery engine.

47customchev, To get your information straightened out you probably need to do some more research. The 7 main story is not right for a 261, there was no Chevrolet 292 until regular USA production of the 235, 261 series of engines was dropped, They were manufactored in South America for several more years and some replacement blocks may have been cast in the USA and sent out later than 1962. I have a 54 style of 235 that has a casting date of 1956, it is a replacement engine and there is no engine number (the one stamped on the flat milled boss just behind the distributor) Also FYI the 270 CI engine was a GMC engine and there also was a 248 and a 302 or 300 and was a completely different engine than a Chevrolet. I am not any type of an GMC guru by any means but we did put the 270 Jimmy in some Chevrolet cars back before there was a Chevrolet six larger than a 235. Before 1954, My high school running buddy had a 46 Chevrolet coupe with a 270 GMC with a Packard 3 speed on the tree, It had dual exhaust, a cam and a split manifold, it screamed. I am familular with the series of engines that replaced the 235, 261 As Gene related that series started with a 230 and 292 and also included a 250 the early models had the same manifold arrangement as the 235 and 261, later versions had the cylinder head and manifold cast in one piece. Gene (Chevynut)is the most knowledgable guy that I know of on the planet when it comes to Chevrolet parts and numbers. He won't give you bum information.
Also the casting date code would be for 1955, not 1965

Sorry, the above posting of casting numbers/year is incorrect. The 3733950 is a 1954, 1955 1st design truck 261 engine. The proof is the high mounted water pump in the pictures. The oil pan gasket for the engine you have will be very different from the 1955-57 gasket. Also it has the "dummy" boss for the motor mount bracket on the side of the block - this was drilled for the 1954 passenger car engine with just the dummy on the 261 truck engine. The 1955-57 version will not have this.

Well after some hunting with the engine casting # with Google I found this site that tells it all.
http://www.97330.com/Chevy_261/261_6.html
And it does have only 4 mains..... oh well.
I guess dad got BS'd on this one but it IS a great engine anyways!
After 48000 miles, there is no viewable wear on the cylinder walls.
Now I can get the correct gasket set.

Thanks!

FYI,back a couple of years ago when I had a C6500 with a 261 engine I bought a gasket set from American Classic Truck parts in Aubury, Tx. Here is a picture from their online catalog.


The set appears to cover both types of engines 54 - early 55 and 55 to 62 (notice the two sets of tappet cover gaskets and the two different water pump gasket sets.)

i also noticed tuo rear oil seals i dont know why they did not give you a piece of gasket paper to go along with the knife and be done

Pushrod, I have never seen a real knife in a gasket set before, but I guess this is a complete gasket set. They probably will sell you a roll of paper if you want to be creative!