Adler's Antique Autos, Inc.
Author of "Notes from the Corrosion Lab"
801 NY Route 43, Stephentown, NY 12168
(518) 733 - 5749 Email
Part 4 of a Series
"What's Under the Hood?
by Bob Adler
There are many identifying characteristics on major truck components, with the engine being the most important. Knowledgeable friends might say, Yup, it?s a Chevy 216 fer sure. It has a tall side cover and two studs poking through the rocker cover. They may be correct, but it?s better to find more reliable sources for identification. The following will help confirm what you have under the hood and determine if the factory put it there.
From this table I surmised the engine is a 1942 or 1946 Chevy 216. However, the internet makes anyone a publisher, which produces a lot of misinformation. We need to use more sources to confirm our engine's exact origins.
Another website, from Inliners Intemational, high-performance 6-cylinder engine enthusiasts, lists 839770 as a Chevy 216ci, 1942-53. Classic Truck Shop's website also associates this casting number with a 1942-53 Chevy 216ci. Neither of these two sources listed the stamped numbers, which appear in the middle column of the table.
My favorite source for casting numbers is the Hollander Interchange Manual. The 16th edition of 1949 says 839770 Chev 42-47 All w/216 Eng. The 23rd edition of 1956 does not list this engine number. The Chevrolet Master Parts List 1929-1942 does not list this number. The 1950 version says 839770 1942-47 all with 216 engine. The casting number is not the part number. The part number, which is 606537, also appears in the 1942 Master Parts List, but it did not have a cross reference to the casting number, so I could not identify it solely from that source.
The factory would season or age these blocks for a month or so, then machine and assemble them. Right after World War II, with a shortage of new cars and trucks, I bet the manufacturers eliminated the aging process. So, the engines would be installed in a chassis soon after the casting date.
This is a good indication that the original engine is in this 1946 truck, and that the builders cast, machined, and installed this engine block without wasting any time.
The date code is D 196 for April 19, 1946. How do we know it is not 1956 or 1936? These date codes repeat every 10 years. GM did not use a casting number on major components for more than one decade. So 1936 and 1956 heads are physically different and have other casting numbers, but would have the same casting dates.
Date code B 18 6 is close to the dates of the other components.
The serial number stamped on the top rear of the housing is DO 19009. The Cars & Parts identification number book decodes this as D for 1946, 0 for a three-speed, half-ton from the Muncie, Indiana, plant. Chevrolet engineering specifications confirms this.
Cars & Parts has a Ford truck identification numbers book as well as the Chevy book mentioned. Both are currently in print and available from This Old Truck. Hollander has reprints of its 1949, 1956, 1965, and 1973 editions currently available. Remember, though, that most of these sources contain some errors.
Internet publishing seems to take print misinformation and magnify it, so always confirm information from the internet. Original factory sources have the highest level of accuracy. The numbers on the three components discussed indicate they most likely came on this truck from the factory, but we can't be 100 percent certain. The owner of this 1946 truck, said his grandfather bought it used. I would say we're 99.9 percent certain the drivetrain is the original one installed at the assembly plant. The components could have been assembled from parts trucks, but it's not likely based on this truck's history.
Note the casting date code is easy to remember and it alone gives a good indication of authenticity. It is found on many components.
Bob Adler is owner of Adler's Antique