It doesn't indicate what the original equipment was. These were the two locations engines were manufactured at the time. Different chamber volumes, port volumes, port locations, valve sizes, etc. Select the portion of the alphabet for your code. The bottom ends were forged and the rods were heavy duty-and heavy in weight.
Each engine will have 3 or 4 number sequences that when combined, will identify what the engine is from. The engine date must precede the car build date, otherwise something is amiss. The date codes are sometimes ambiguious, because they don't have the whole year, only the last digit with a few exceptions. Roller or flat tappet cam, one-piece rear seal 14093638. This one produced in 1971 at Tonawanda with engine serial number 73170. Camel hump,no accessory holes,64cc chamber 3917292. Aluminum, Pontiac Super Duty version of Gen.
Gen I small-block Chevy engine. The engine plants now stamp a source, production date and type on serial pad. The Casting Numbers to the right are found just below and to the right of the Distributor on the passenger side. Thanks for the post man. If you already know what you're doing, Chevy Engine Codes are listed. The next set of numbers you will find helpful are on the flat part of the Distributor Deck.
Info Added: 9 July 2006 says that you are visitor number: to the Please Report any Broken Links or Pages that do not load properly. . No side motor mounts 3737739. But numbers correct is not numbers matching. Each individual stamped character was placed in a holder and secured before the engine block was struck by the employee responsible for doing this task. The final digit could be a year code. These blocks are fine if you don't care about the roller cam.
Note: This is not meant to be a replacement for sonic testing the bore thickness. Beginning about 1969 the suffix code became mostly three characters instead of one or two. Camel hump,64cc chambers,accessory holes 3927188. Here's I've been working on since 2005. It can be one or two letters on 1969 and older engines, and three letters on 1970 and newer. Roller cam, one-piece rear seal 14088548.
Chevrolet had introduced its popular small-block V8 in 1955, but needed something larger to power the medium-duty trucks and its heavier cars that were on the drawing board. Again, it either matches or it doesn't. Big block on the right side of engine above the oil pan rails. Casting Date Small block casting date is located on driver side rear of block on flange forward of bellhousing. Please Note: This info is incomplete and I am still trying to compile this list.
That eliminates the 400 and 305 possibilities. There's other possibilties as well. Essentially this limits the amout of information you can learn about the motor. Some newer V8s have it on a little machined pad just above the timing cover. This will usually be found stamped next to the engine code.
The stamped code on 30s-mid 50s engines includes some variation of the car model code, and a sequential engine number, but no date information. Again, the location on the block may vary between the plants and years but one change was made in 1968. There could have been a hold up in production and something was pulled. Could this be a dealer replacement? The location of this code depends on the type of engine, typically as follows: Small Block Chevy: Machined pad in front of the passenger side cylinder head. A little engine degreaser and a wire brush often makes this job easier.