[Kurt L71S]

I am running the numbers on a 1971 LeMans Sport 350.
Block Code 21A 130527- Pontiac, 1971, Atlanta, Engine number
Block Casting 481990-71/72 350
Date Code B251---February 25th 1971 350 2 bolt main
Intake Code 9794234-68/69 350 Qjet 1x4
Quadrajet Carb---7040262 XA 2629---1970, Federal 4 bbl, Pontiac, Automatic.
XA---Casting plant 2629---Sept. 19, 1969

Found this piece of information regarding the numbers on the engine..

Pontiac engines have block code. This code will tell you the year it was to be used. However, these codes were used over from year to year. Together with the casting code and casting date you can determine what the engine is. Starting in 1965 Pontiac began using a 2 digit letter code. Above the 2 digit code will be the motor unit number, which is either 6 or 7 digits. It is important to note that it is not related to the VIN number. As a general rule, "W" coded blocks are manual transmission and "Y" coded blocks are automatics. And most of the "Z" coded blocks are also auto. The "X" coded blocks are a little of both.

All engine blocks have a casting code. This code will tell you the year it was to be used. However, these codes were used for more than one year and could have different machining or even different main caps. Casting codes for 1955 to 1963 are found on the passengers side of the block. Casting codes for from 1964 to 1967 are found on the distributor pad, except the 421's. Casting codes for from March 1967 on are found on the rear of the block just behind the number 8 cylinder.

Displacement ID's were cast in the side of the block starting with the 1968 428. A 428 was cast on the side of the block and in the lifter valley was a 28. In 1970 the 350 and 455 had their size cast in the side and a 50 or 55 in the lifter valley. The 400 also has the 400 on the side and 00 in the lifter valley, but not until 1971.

Can someone tell me if I'm thinking correctly...
My LeMans VIN number is 237371P116361
Engine Code is 21A130527
According to the info I found above the two numbers are not related.

Confusing to say the least! Everything I have found leads me to believe this engine was meant to be installed in my car, but.....???...
Thanks and I hope this helps some other with their questions about numbers.