The Stovebolt Site Forums The Shop Area Engine Shop Deciphering my Chevy stovebolt

Hello, I'm new here. Still trying to figure out how to upload some pictures of my engine to facilitate the deciphering of my engine. Until then, I hope someone can help me with the info I already have. To start off, the engine is painted Chevy Orange. It has a Rochester Carburetor, I imagine a single barrel but not sure. The valve cover has the breather in the front and the "Chevrolet" script written the length of the cover, it is held on with 4 bolts like on a 235 which it very well could be. Now for the important information, I've checked every website that deciphers the cast number and I.D number and none matched, here they are, I.D number is:FO4TILB The block casting: 3789717 Right above the starter it has written D41.
Thanks beforehand for any help, meanwhile ill keep trying to figure out how to get some pics on here.

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I got under my truck and took the best pics I could of the engine and its numbers. Upon further investigation I found out that I was one number off. Where I originally thought it was 3789717 was in fact 3769717. This showers that I am the proud owner of a 1959-1962 261 C.I Stovebolt! I couldn't be happier. The thing drives like a freight train. Here's the pics.

Casring #

Overall Engine pic

my loves

Thanks for all the help and interest

I've had this truck for a few weeks now and am just finding out what treasures it holds. I never imagined it would have a 261. If it would have had a 235 I would have definitely gone bigger, but this engine is sweet. Can anybody give me any info on these beauties? Pros and cons? Thanks guys

3789717 is the 1958-1963 261 block casting code.

Post the head casting code and the head&block date casting codes and you/we will learn more.

Also, please post a photo of the Engine Serial Number (If you have not already done so).

The second and third links in your post above are the same photo.

Hi Tim, the id number doesn't show up in the pictures, the script is very fine, but by eye I can see it, the code is : FO4TILB
Would the head casting code be under the valve cover? I'll look for it. I'm going to be painting the rims today, that's why the truck is up on stands. Today is a nice sunny day for this in Northern California

A pic of the progress, they will be painted in about 3 hours when all is warm. They are the stock steel wheels 16x5 inches with Coker white wall tires
ready to paint stock steelies

Your Engine Serial Number is FO4TILB - that code was often used as a title/registration ID.

In 1957, the LB at the end indicated a 3100-4000 series truck with RPO 408 (265 V-8) or RPO 409 (265 or 283 V-8)

http://www.1954advance-design.com/chev-specs/1957-t-ser.pdf

FO4TILB
F = Flint, MI engine plant
O4 = ?? = should be a month number = 4
O4 = 4 = April (which supposedly should have been just a 4, but a O4 or 04 might have been used)??
TI = ?? = should be a day-of-month number = 11th??

We cannot determine the year of the head/block casting without date casting codes.

You might have a replacement engine/block - any Engine Serial Number could have been pressed into the block

The locations of all 261 codes are shown at the link I gave above.

The head casting code is outside the valve cover - the head date casting code is inside the valve cover.

I wish it was warm enough here to work outside.

Thanks Tim, I'll check for the head casting code a.s.a.p where are you located? I'm just stoked it's a 261, I knew this thing had way more power than my 216 or what I imagined a 235 had.

I am now near Albany, NY, but we will be moving to eastern NC no later than June 2016.

The 261 is a fine engine. It looks like a "stock" engine (to most people) and it has a very noticeable increase in power (without doing anything to it).

Hey Tim, here's the only numbers I saw on the head

head id number

I appreciate your help, thanks

North Carolina, nice, I imagine the weather will be similar, I'm sure it's a beautiful area.
About these 261's. Do they do well with a double carb setup? I wouldn't do it right away, it's running perfect as is, but maybe eventually to get some more power from it. I just ordered the original style throttle-choke bracket that goes on the carburetor, the previous owner home made one, looks Oakey but works, it's to high though and is not allowing the air cleaner to seat properly.

Nevermind, I'm having some tech issues.
Ignore this Post

That head casting code ( 848 & 850) has never been explained here.
It is shown in Photo 4 at the link provided in my first post above.

I see, well, when I get the valve cover off, I'll inspect the number inside, in any case, I'm quite happy my truck has such a good engine.

"About these 261's. Do they do well with a double carb setup?"

I have tried a few types of dual carbs.
- dual-Rochester set was "too much carb"
- dual Carter-Weber (from Langdon's) was "too little carb"

I now suggest using (on a 261) a single carb with adjustable jet/jets from a slightly larger engine, like a 270 or 302 GMC (270 GMC Zenith one barrel, or a 302 GMC Holley two barrel). The Holley might be a little too big (even with the adjustable jets) and it needs a hard-to-find base-adapter. But, it works very well on my 060" over-bored 261.

Dual-exhaust manifolds are a possible/easy adaptation, if you want to route dual exhausts.

Get your engine/running/tuned with what you now have. Then decide if you want to mess with carburetion/etc.

That's good advice Tim, thanks.i know it has a Rochester, not sure how bog, but it runs nice, I have read that the charters are much better though.

Charters = Carters

Sweet has two Carters (from 216s, I think) on his 261. It runs/behaves very nicely.

Wheels are done, they will look sweet on my 46 Chevy. Can't wait to put them on. Running on Coker white walls 6.00 16's Original wheels all painted

I too "lucked" into my 261. Before I owned one, I had never heard of it. Then when the person whom I bought it from told me about it, I took a chance.

I haven't looked back since.

I started my fresh 261 with dual carbs and exhaust. In the first year I swapped the carbs to Carter YF's. Most reason being the chronic leaking of the Rochesters.

The YF's were a DIRECT plug in for Rochesters. Driven them over 20,000 miles and have enjoyed each one...

Looking forward to watching your progress....

I also lucked into my 261 (back in 1972). The original 235 was cruising with 0 psi oil pressure (and could not get up Afton Mountain in 3rd gear). Leon had one for sale from a school bus at a lower price than a 235 ($100, I think). He told me what would be needed to get it to work in my Suburban (water pump and fan pulley). Best buy I ever made.

Hey DB. Yeah, I knew I had something special. At first I was a bit down that the truck didn't have the original engine, but I knew 235's were better than the original 216's. So I went with it. My dad and I drove it from oakdale Ca. To Eureka Ca. That's about 400 miles without a hickup, it was actually pulling better the further we drove it, the engine seemed to loosen up.We gave it an oil change previous to departing and I bought an extra 5 quarts preparing for it to burn at least a quart in a few hours. To my surprise it didn't burn any oil at all! It had so much power and torque I kind of felt it wasn't a 235, I thought maybe a 250. More than adequate power for the simple tasks I have planned for it. Doesn't have an external oil filter, I'm thinking of adding one for longer life. Do you guys suggest adding msd ignition? It makes older engines run much more efficiently. Another question, when I go to change the valve cover gasket and the exhaust manifold gasket, are they the same as a 235's? What is the greatest difference between these two engines? Are carter carburetors that much better? Which intake manifold did you end up going with DB? I'll have to check out your pics. Thanks for all the info

Tim, you've had your 261 since 1972!? I wasn't even born yet haha, very cool. Have you made any mods to it that you would suggest? Does it have the external oil filter?

Can you take a photo of the other side (driver) of your engine? Your block has the ability to do either a bypass filter or full flow like in today's engines. Take a photo so we can see the side of the engine under the manifolds.

If there isn't a filter on it now, I suspect the P.O. has the motor setup in bypass mode and an external line is run between the 1/2" NPT fittings. You have the option to do either with that engine.

A little bigger carburetor and/or a carburetor with an adjustable jet might help get a little more power. I have several carburetor combinations (some are shown on my website)

I suggest that you get all parts working well and just drive it. It is a very good engine.

I have used the original 58-63 full-flow filter assembly, but now I am using an aftermarket full-flow spin-filter assembly (a long story). I'll probably eventually switch back to original full-flow filter, because it looks cool and it has a safety bypass in its "head" (I do not know for certain if my spin-on filter head has a "safety" bypass in it).

I'll take a picture a.s.a.p. When I get back from work. The wheels are back on and it's looking fine. It's coming along nice. Thanks for all the help guys.

I am mocking up new spin on housing in a new location.

Rocket and I will use Old Yeller to get everything in order before taking the GreenMachine apart for a bit.

Chris,

Will your spin-on filter-head have a bypass feature (in case the filter gets clogged)? As I recall, you have a 1959 261.

If yes, would please post a manufacturer/part-number?

Maybe they all have a clogged-filter bypass? Or, maybe it does not matter - change the filter regularly?

Thanks,

Hey guys, here's the pictures I just took from the carb side of the engine. Also a picture of my Rochester carburetor with someone's "cool" homemade choke cable bracket that doesn't allow the air cleaner to seat correctly. I've already ordered what I hope is the correct bracket.
engine carb side

home made bracket

with recently painted wheels & ww tires

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Gabriel, your engine is setup in bypass and the NPT fitting are plugged. You can add a bypass filter and plumb it in with a few reduction fittings.

Tim, the housing is not what has the bypass feature, the oil filter does in my case. Here is the spec sheet of the filter I use on my truck. If you look below the photo in the information you will see 8-11 lb bypass relief valve setting. A quick look at Fram.com also shows "relief valve technology".

My thought is that would be better, no maintenance on the valve.

Thanks, Chris,

I think that some filters/heads rely on a "clog" by-pass being in the filter head or in the block. I have never had a problem, but I carefully/regularly check the gauge and change the spin-on filter. I'll check the part number on my filter (I think it is a Fram), just to see if it has a by-pass in it.

Hey Chris,

Could I go with a regular external oil filter like a normal light duty engine would have had back in those days, like let's say a fram system? This truck will be used, but nothing too demanding. I really like my fram oil filter system that's on my 216. Looks nice and goes well with the engine. Do you happen to know any place that has done it so I can copy it or is this one of those things I just have too see allot of pictures of previously done systems and try to copy them? Thanks for the info, I know it's going to run much longer with one of these.

What type of "fram system" oil filter are you referring to?
Post a link to a photo, if possible.
Normally, a 216 would have a by-pass filter.

I think you now have a 58-63 261?

Does it now have a filter on it?
Post a link to a photo, if possible.
A 261 might have no filter, a by-pass filter, or a full-flow filter.

You will most likely want to use a filter that matches what is now being used on your 261?

It doesn't have a filter system yet Tim. My 216 has the Fram by-pass oil filter system. I would have thought the 261's had a filter system, but I guess not all did. They come up for sale on eBay from time to time I just have to keep my tees open for one.

Be careful about the filter system you use.
1. Your engine might never have had a filter - you could then use either type filter, I think.
2. Your engine might have had a by-pass filter (you could use that, or your Fram unit, or change to full flow)
3. Your engine might have had a full-flow filter as shown at that link.

If your engine ever had a full-flow filter, YOU MUST NOW USE a full-flow filter, or use a tube/pipe/hose from one port in the block to the other port in the block (and use no filter).

Can you take a photo/photos of the left side of the block? The exhaust pipe will not make this easy.

Here is an illustration of a 1960 full-flow oil filter.

Look at that side of the block, and see what you have in the holes in block where you see the lines in the illustration.

If you can post links to photo(s) of your block, where the tubes attach in the illustration, we might be able to help you move forward.

Best thing you can do is go to this document and look over the pics of the dowel pin that governs if you have full flow or bypass. Very important distinction because if you use the wrong one you can starve the bearings.

http://devestechnet.com/Home/TheVenerable261

Lots of great information there about your engine. It appears it's set up for bypass. We know because the front outlet is not connected to the rear inlet. They must be connected together if the dowel is pushed in. Knowing that, you can go for any bypass system you want to use, or change it over to a full flow oiler.

If you

I was going to change the transmission oil and the rear end gear oil today, I went to oreileys to pick up some gear oil thinking of getting a quality brand like royal purple or something similar so I wouldn't have to worry about it for years to come but the counter guys couldn't tell me which weight I should get or even if I should use regular gear oil. Do these classics use regular gear oil? They put me into doubt. What do you guys say?