Hello, I need some help identifying what kind of motor i have. My father did an engine swap on his truck before I got it and I want to start to rebuild but can't figure out what I have. 3877178 Con 2. L 15 G F1216FM These are all the codes I've found.
The 3877178 is the engine block number for a GM inline-6 engine that was used from 1962 to 1978. It was used in Buick and Oldsmobile vehicles and had a displacement of 230 or 250 cubic inches.
Casting date of L 15 6 (not G) Dec 15, 1966, would make it an early 1967 model year engine. Look closely at that casting number again, the last character is a number, not a letter. F1216FM F means a Flint built engine 12 16 is Dec 16th FM is the suffix code As a 1967 engine, then the FM suffix means that it's a 155 hp 250 from a full size 1967 Chevy car, originally with a Powerglide transmission. It was pretty common to get a good running car engine from a junkyard, to keep an old truck running.
OK that makes more sense. I was originally thought it was a 6 too but was second guessing myself and tried a G. So if I'm understanding correctly, 155hp 250 inline 6 engine? I'm just worried to order parts and them be incorrect.
yes, it should be a 1967 Belair 250 6 cylinder engine. The distributor on it is the HEI from 1975 or later.
I just found FM is a 65-67 big Chevy p***enger car motor but it doesn't specify 230 cubic inch or 250 cubic inch. The 250 has a quarter inch longer stroke than the 230.
I was doing allot of my searching on the gm heritage center website and going through the pdf files of the manuals. I was wasting my time looking at trucks if it's a p***enger car motor
Source of my post. Google 3877178 GM Motor and this is word for word copied. The 3877178 is the engine block number for a GM inline-6 engine that was used from 1962 to 1978. It was used in Buick and Oldsmobile vehicles and had a displacement of 230 or 250 cubic inches.
The casting number doesn't really tell us much, since the same casting was used for a decade in a whole bunch of different vehicles. But anything that lists the Chevy six as having been used in Buick and Olds vehicles, and not mentioning that it's a Chevy engine, is not a very reliable source. We can tell it's a Chevy engine just by looking at it, and having worked on so many 1960s-70s cars.
I'm going with that FM being correct for a 67 full size car 250. I scrolled the whole GM heritage center vehicle info kit for 63 trucks and no serial number info.
This is the book that has this code. I also have several other old Chevy parts books, 29-59 that covers cars and trucks, 46-64 that covers cars, 38-69 trucks, and 46-72 trucks. They're pretty handy. For pre-1960 parts books, you can look on tocmp.
The Jalopy Journal
