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I'm a newbie, trying to verify that an engine I'm considering buying is a '54. The serial number on the block is 3835911, and on the head is 3701887. Can someone point me in the right direction to confirm this is a 1954 235? Thanks for the help!!

Wait to hear from someone with better documentation.

However, the block code looks like one from an October or newer 1953 Corvette 235 and was also used on 235s used in Corvettes and Powerglide equipped cars into 1955.

My information on the head code must be wrong: 1953 235

Here are locations of other codes. The date casting codes and engine serial number will give a better idea of year in which it was installed (and the applications).

Some records also show:
block casting 3835911
with head casting 3701887
Truck 1954-55.1

Passenger 1954-55 Mech. cam
but with the 848 or 913 head

The 3701887 head was also used in 1953 passenger & truck with the 3701946 block, mech. cam.

Like Tim said, post the block date casting code, it will give you a better idea.

The code stamped by the distributor will also confirm original application.

I have a block with the casting code of 3835911 and a distributor pad stamped number that shows up as that for a 1954 Corvette. However, the block is definitely a 261, as it has the steam holes and a 3-3/4" bore. I was told by the previous owner that the short block was purchased as a replacement engine in the mid-seventies to be installed in a '54 Corvette. I remember seeing on the Inliners' site a few years ago of another 3835911 block that turned out to be a 261. It was also believed to be a replacement block.

The casting numbers and the distributor pad numbers are just evidence, not proof, of what the block really is. I own or have owned five 261s, and ony one of them has both numbers being correct for a 261.

Hoyt

Hoyt,

To help us all better understand the 3835911 block will you post your distributor pad stamped number and the block casting date code.

There are 2 different 3835911 blocks. One with small cam journals and one with large cam journals that was for the 53-55 corvette.

Thanks for your help.

Thanks for the help!

Tom, et al.,

Here is a photo of the block, and here are close-ups of the casting number and the distributor pad number.

Hope that this helps. Remember, this 261 block was purchased, new, in the mid-seventies from Chevrolet to put in a 1954 Corvette.

Hoyt

Hoyt,

Thanks for posting the pics.

I'm still confused.

Is that a "captain's bar" on the passenger side to the rear of the distributor. Are there any bars on the driver's side.

Also, if you will, is the oil line hole on the driver's side 1/2".

Hope you can help.

Tom,

That "captain's bar" you see must just be a shadow; there are no bars on either side of the block. The fittings for oil filter lines are the small, 1/8" NPT size. I have two late 261s with the factory 1/2" NPT holes and I put 3/8" NPT threads in the 1954 261 that I have in my street roadster , and the difference in size is obvious. I will put one of the later 261s in a pickup truck project that I hope to start this summer.

As I said before, the captain's bars,casting numbers, and serial numbers are just evidence, not proof, of what the engine really is. However, I have never heard of a block with 1/2" NPT fittings for the ol filter that was not a 261. All full-flow conversions that I have seen used the 3/8" NPT fittings, but that is not proof that there is not a 235 out there with 1/2" fittings.

Hoyt

Hoyt,

I couldn't tell from the pics if there were captain's bars or not, that's why I wanted to check with you.



You have open my eyes and I agree that it is just evidence.
Because captain's bars, block casting numbers, and engine serial numbers can be changed, altered or removed.

The factory block casting number 3835911, has always been a 235.
It does appear that your block casting number has been altered.
The 8, 5 ,1 ,1 have been altered to make the casting 3835911.
Your 1954, 261 block casting, could have been 3733950 before it was changed.

Maybe some will post a pic of their 3835911 block casting so we can see what it looks like..

Tom,

Here are some more photographs of the 261 blocks.

This is the casting number on 3733950 block in my roadster.

Here is the driver's side of the 3733950 block.

This is the driver's side of the 3835911 block.

It is hard to believe that someone has altered the casting number on the blue block from 3733950 to 3835911. There would be some marks left from where the final two digits (the "5' and "0") were cast into the block. The shadows and flash reflections on my images make the surface look a lot rougher than it does with the eye and diffuse light. Also, a good friend of mine was involved with the original purchase of the blue block and its subsequent history, and he would have been aware of any alteration.

The blue block surface is also very clean where the captain's bars would be. As the images show, a circular boss is cast into the 3835911 block on the driver's side where the captain's bars are located on the 3733950 block.

I had never noticed that the Chevrolet Parts Catalog shows the 3835911 casting number for two different part numbers. Which of the 3835911 blocks have the small cam bearings?

I would like to see what the markings on some other 3835911 blocks looked like. It appears that Chevrolet used that casting number for more than one application.

Hoyt

Something I'm wondering on that block is what the real history of it is. Perhaps the po didn't know or didn't want to tell you in order to make the sale. From the pics you've posted, it's definetly a pre-'58 engine, and the casting date confirms that it's a '54. Since we know the serial number was falsified somewhere along the line, and the casting number does come up as a 235, could it be that the engine was rebuilt/altered somewhere along its life? What I'm getting at, and no offence to anyone, is could it possible that someone overbored the block .187" to make a 261 out of it? I know that is well over twice the max safe overbore for a 235, but it could be possible somebody could have tried it. I personally can find this beleivable, as I have an engine that something very similar was done to by a po to get "more power". In my case, the engine is a Ford 8N tractor 4 cylinder. The guy my Grandpa got it from had taken the sleeves out in order to install larger pistions, he also had the head milled. That didn't work out very well. Grandpa, Uncle Ralph, and my Dad put new sleeve in w/stock pistons, plus a doubled up head gasket, and the engine ran fine after.
I'm just throwing out a theory here, as from what I've seen, 99% of the time the cating number and serial numbers are correct to what the engine is.

Jim Carter indicates that the smaller cam journals were used on 235s through 1954 (probably 1955 1st). That would conform to the use of 3835911 through 1955-1st as shown in the Master Parts Catalog (in the page-link given by Hoyt).

The cam bearings,starting with GP 0.539,
showing small and large cam journals
and the years are listed here.

http://chevy.oldcarmanualproject.com/1929_57chevyparts/57cmpc0142.htm

I have a block with cast#s 3835911 and sieral #0420333f54m.Im trying to findout if its corvette too?

It looks like air chevy's question has been answered in this other post.

It is true the 911 block was used in 55 1st trucks, but there was a change mid year 54 from small journal to large journal cam. You can tell which cam you have by the width of the distributor drive gear. The small journal cam gear will be about 3/8" wide, and the large journal cam will have a 5/8" wide gear.
The GM parts book shows both large and small bearings for 54.