Decoding a 3692703 235 Block

Your Visual Guide for a 1950-51 GM 235 engine with Casting number 3692703.

There have been many changes and evolutions to the 235 over its long history. This Photo series hopes to highlight the differences so you will have an easier time understanding your current engine and what differences may appear in a Replacement 235 Engine.

The 50-51 engine block shares many similarities to the Chevy 216 engine.

GM 3692703 was only available for two years.  In researching, it is only listed in the Chevrolet Master Catalogs in the 1929-1950 catalog.  It doesn’t show up in 1952 or 1954.

To start, let’s look at an engine brought in for a rebuild. It still has the external parts attached to give you an idea of which parts come on this block with Casting# 3692703.

Note this engine has a Flexplate, meaning it mates with an Automatic Transmission.

1950 was the first year the new Power Glide transmission debuted along with the new improved 105 H.P. 235 engine.

Enjoy the photos.

1950 Chevy 235, casting 3692703 long block engine before rebuild

Let’s Decode the Block Numbers

Casting Number: 3692703
This is a Second Generation (1941-1953) 235 engine with Low-Pressure Oil System (internal lubrication).
This engine block is a 1950-51 block.

Date Code: I 18 0
[Month] [Day] [Year]
First Letter codes (A=Jan, B=Feb, etc.)
So an I means September.
Day is the 18th day of September.
Year is a Zero (0), this correlates with the Block Casting Number, since it is a 1950-51 number, then the Zero means 1950.

Serial Number: HADII36979
Combines symbols for model year, car type, plant, then serial number from each plant.
H is for 1950
A means Passenger Car
D – 235 with Power Glide– Passenger

II – could not find source to decode

36979 serial unit number from plant

Breakdown and Reference materials below.

The Oil Pump Pickup Tube

There are different versions/variations of the Oil Pickup Tube across the Years, early and late model years.

Parts listed for sale online state a range of applicable years, including the 50-51, but they are not all the same.  They are not interchangeable.

These two years utilize a version with a Support Upper Pipe that Must bolt onto the Third Main Cap.
It is not the floating type.

Photos of Installed the Oil Pump  and Pickup Tube with Screen.

Babbitt Rods

Originally, this engine came with Babbitted Connecting Rods.
During the rebuild, we converted them to Insert Bearing Type, now they utilize modern bearings.  Connecting rod Casting number for these rods is 3835274.

Oil Pan

Early GM 235’s have distinct straight edges.  Opposed to later versions that bump out on one side.  It has Troughs and Oil Pipes.

This oil pan has 2 vertical baffles.

Front Mounting Plate

GM 3692703 Engine Block mounts only from the Front, No Side Mounts.  There are no mounting holes on the sides of the block.
This bolts onto the Timing Plate Cover like you see in the photos.

If you purchase a different year engine, most likely it will have a different configuration.  It may have holes on the sides, either in Front or in the Middle.

You will need to purchase Brackets adapted for your year, you may need to make modifications.

This is the reason we ask customers where thier current engine mounts to the frame when they inquire about buying a 235 engine.

Not all 1950 235’s came with a Powerglide Automatic Transmission.

It was an Upgrade Option added to a Regular Model.  According to the 1950 Specification sheet, it could only be added to Deluxe models. For an additional $158.50, you could have a Power Glide Transmission.

See detailed information from the 1950 GM Vehicle Information Kit pages.

Remanufactured 50-51 Chevy 235 Engine

Photos of completed engine from all sides.

That wraps up our details about a 1950 Chevy 235 Engine with Casting # 3692703.

If you have any questions about getting your engine rebuilt, shoot us an email with your details, using our Contact Page.

If you are interested in purchasing a Chevy 216 or 235 Remanufactured Engine, see our GM store page.

We may have engines, Short and Long block, not listed yet.

Thanks for reading.