Chevrolet 235 Engine Serial Number
STOVE BOLT CASTING NUMBERS. 235 Block Casting. 3629703 50-52 235. 3692703 50-52 235. 3692708 50-52 235. 3692713 50-52 235. 3835692 50-52 235. Engine Casting Codes & Serial Numbers 1954-1963 Chevrolet 235/261 inline 6 cylinder (NOTE: these photos are from a 1960 261 engine; however, 1954-63 235 & 261 codes should be in the locations shown below).
The Casting Numbers to the right are found just below and to the right of the Distributor on the passenger side. They are notoriously very hard to read and often people make the mistake of thinking a '3' is an '8'. Clean the area thoroughly and use a nice bright flashlight. This is usually a 7 digit number and each letter/number is about 1/2' tall. A little engine degreaser and a wire brush often makes this job easier.
How Do You Decode A Chevy Engine Number
The next numbers we need are the ones just below the Starter on the passenger side. This one will have a CONveyor Number and beside that a usually four digit letter/number combination separated like this: X XX X. For example, the first X will be a Letter from A through L. A = January through L = December. The center two digits are the day of the month. The final digit is the year the engine was made WITHIN the years that you narrowed it down to when you deciphered the Casting Numbers to the right.
The next set of numbers you will find helpful are on the flat part of the Distributor Deck. This machined flat area has serial numbers stamped into it. If you have looked very carefully and find no numbers there, chances are your block is classified as a Replacement Block and will have no numbers stamped on that deck. The numbers you are looking for are stamped (about 1/4' high) and usually a Letter followed by three Numbers and ending in another Letter (or two). The first letter is almost always F since most GM engines were made in Flint, Michigan. The following numbers are the month first followed by the day of the month. The trailing letters denote what the engine was installed in. The possible Letters for the last ones are explained in the chart below.
I am trying to properly identify the engine and head. We know that the 'engine was replaced'.
The casting number on the head is 383540. Based on the information I can find this is a 1949 head. So possibly only the block was swapped.
The casting number on the block is 3835497 which I believe is a 1950 - 1951 block for a passenger car.
The confusing part to me is the serial number stamped on the block. It is JBA660827 which I think is a regular 1951 truck engine from the Flint plant.
Any ideas why there appears to be a discrepancy between the casting number and the serial number?
Thanks!