The Stovebolt Site Forums The Shop Area Driveline 3836848GM and GKT 134 Transmission

Hello.
Does anyone know if the GKT 134 4 speed transmission can fit the 3836848GM head motor, or can only the SM420 type be compatible?

The casting numbers from this old Chevy G506 fire truck engine are 3836848GM, 15GM, 18GM with an unreadable seven digit number. The bellhousing # said 839257 GM.
The transfer case is original from the G506, but the casting number is illegible. The bellhousing and the transfer case seem original from the G506 model but what type of transmission would the truck have carried with this engine?


Regards

The GKT-134 is known here as the “crashbox” because it lacks synchronizers. You’ll
Want to use the SM420
As it is synchronized except for 1st gear, which you’ll only use from a stop.

Also there should be numbers just above the starter. Let us know what they are so we can positively ID your engine.

Thank you for the help. It is hard to make out but I think I see CON2 F 6 8 above the starter. On the same side I see a 3/9. On the driver side I think I see 3835697 below GM18.

The main thing is what trans. will the transfer case bolt to with the correct output gears if a married transfer case? If divorced, no matter. What engine do you have?

Ed

I just took off the side panels and discovered the casting 3733949.

The casting that I could read so far are the following:

On the top is the vintage 1950's Chevrolet script emblem.

Driver side:

3836848 (Head)
GM 1
-----------
GM 16
3835637 (?) Hard to read.

Passenger side:

CON 2 F 6 8
GM 16
-------------------
3733949 (Appears at the end at the bottom).

You Block Casting number 3733949 is a 235 for the 1954-55 cars and trucks. With a date code of F 6 8 that tells me it's a replacement block that was cast June 6th 1958.

CON 2 is the conveyer it was cast in...

Is there a number stamped in the flat machined surface next to the distributor?

The 235 head 3836848 was first used in 1953 and is a desirable head to have.

Mike B

[img]https://www.stovebolt.com/ubbthread...umber/25097/filename/20201128_092933.jpg[/img]

In the distributor area I only read CON 2 F 6 8 (3?), GM 16 3733949. When I removed the rectifier regulator in the carburetor area I discovered a casting that seems to say 3838922, GM 37.

Standing beside the engine looking directly down at the top of the distributor you should be able to easily see a flat machined pad on the block just toward the firewall from the hole the distributor passes through. The numbers stamped into that pad will tell you all you really need to know. If that pad is not there you probably have a replacement engine or some other oddity.

I checked the engine and could not see the pad. On my first post I added a photo of that area. It was probably a replacement part then.

I went back with a sponge and my phone's flashlight. I cleaned where the distributor is supported and there is a serial number SO 627P. The engine casting number is 3733949.

That serial number doesn't match anything Chevrolet used that I'm aware of...

Does it match up with any of the other serial numbers on the truck or title?

Can you post a close-up picture of that serial number?

Mike B

1955 235 is what I see from the casting number on line

Mike, I just added the photo to the first post of this topic. Yesterday I removed the distributor and the cover of the block to see if there were more numbers, but there was no other than that (SO 627P). There isn't much info on the title either.

There should be a serial number on the title that either matches the Body/Chassis number or the Engine number, that's why I asked if that SO627P was on the title.

Bottom line is I believe it's a replacement 1954-55 235 engine cast in 1957 and those numbers could be from the shop that sold or installed the engine for their warranty records.

Mike B

Thanks, Mike. I am preparing with books to rebuild the engine but am doubting myself. I asked my regular mechanic about it, but he's dedicated to modern engines. He is checking with some older mechanics to see if they have any familiarity. Do you know of anyone in the Westminster or Baltimore area who specializes in the stovebolts era?

Regards

Sorry, I don't know of any shops that specialize in Stovebolts. I would think any good machine shop in your area should be able to do the basic machine work needed so you can rebuild it yourself.

Maybe someone else can help.

Mike B

Thank you, Mike.
Today when I removed the radiator, behind the propeller I found the casting 838403 GM.