[72LuxuryLeMansLa.]

How do I/ where do I find information on decoding the codes stamped on my block and heads. I just bought a 1972 Luxury LeMans. This is my first Pontiac and I'm not familiar with them.

Thanks for any help you can provide.

[ryan389]

GO TO WALLACERACING.COM THEY HAVE WHAT YOU NEED.

[MescaBug]

Yeah, or www.teufert.net

Or just Google "pontiac engine codes" or something similar. There is a ton of information out there.

How do you like your Pontiac? . Any pics?

[72LuxuryLeMansLa.]

Originally Posted by MescaBug

Yeah, or www.teufert.net

Or just Google "pontiac engine codes" or something similar. There is a ton of information out there.

How do you like your Pontiac? . Any pics?

I love it, my dog loves it, my friends love it, Hell people role down their windows at traffic lights and chase me down on the freeway just to tell me they love it!

This is not the car to drive if you are trying to fly under the radar!

Check the tech forum for 72 Lemans, I posted the pics there before I figured out they belong in the lobby...

[WDCreech]

Since this is your first Pontiac, you may not know where to find all of the needed codes, so I'll post a couple of pictures. Post the codes, and we'll tell you what they mean.

[thebuick]

ok so im going crazy trying to figure out this motor in my car here is the block number next to the water pump [ c ] 473795 YX I checked it 3 times I checked different block ID sites and no luck I was told it is a 400 but im not sure of that or of the yea. Can anyone help me out thank you

[gtofreek]

In the pics above WDCreech posted, they show which numbers you need to look at. The hand stamped numbers in the front of the block, under the passenger side head, don't really mean much to you, but the two letter code under that does. You need to look back by the distributor to get the date code off of it. That will be 4 digits, starting with a letter. The letter signifies the month[A-Jan, B-Feb, C-March, etc.], while the next two number are the day of that month, and the last number is the last number of the year. If the block was cast in the 70's, it will also have the year cast in there. In Mr. Creech's example, it will be the "74" next to the distributor hole. 60's blocks don't have the year cast in, just the date code.
Then you have the block casting number on the passenger side bellhousing area. The main numbers you need are the date code[most important as Pontiac re-used the front block codes over and over throughout the years].

So, to make a long story short, get the block casting date code, and the block code under the front passenger side head[two letters,unless it's an old 64 or older block, then it will usually have two numbers followed by a letter], and look them up here. Remember, that a block produced in or after September, will be for the following year.

http://www.wallaceracing.com/enginesearch4.htm

The head codes are usually on the center exhaust ports.

[Held for Ransom]

Originally Posted by thebuick

ok so im going crazy trying to figure out this motor in my car here is the block number next to the water pump [ c ] 473795 YX I checked it 3 times I checked different block ID sites and no luck I was told it is a 400 but im not sure of that or of the yea. Can anyone help me out thank you

The (473795 is the EUN (engine unit number) and was used by Pontiac in case a warranty issue came up. The ( started in '70 sometime. The YX was the usage code. The Wallace site show these years...

[ponyakr]

As said, the 2-letter code, by itself, doesn't mean that much. According to some sites the YX code you mentioned was used on different size engines from the 301 on up thru a 455.

http://www.pontiacpower.net/engcode01.html

The best way to positively ID your engine has been mentioned. But sometimes the casting number of the block cannot be seen when the engine is still in the car. If so, you can look at the sides of the block to help ID it. If it's an early to mid '70's block it will have 5 motor mount bolt holes on each side, and the cubic inch size will be cast into the sides of the block.

I'll mention one more thing. You can't count on the big number, back by the dist hole being correct. There are XX blocks cast in '77 which have the number 74 by the dist, and others with no number at all. And I've seen one 455 which had no number by the hole, but had a #8 in a lower position.

There are lots of exceptions to most ID rules, and all sorts of weird stuff happened on the assembly lines.

I am well aware that some prefer certain ID sites and charts over others. So I don't need reminding here. Use whatever sites and internet info you prefer.

[thebuick]

I crawled all over the distributer area cant see anything [ motor is in the car ] ill crawl under and check for more numbers thank you everyone

[Matt Meaney]

if the block has the serial number (also referred to as the vin number) on the front, you can use that to determine the year. the second character in the serial number is the model year that it was used in. using WDCreeh's picture as an example, the serial number is: 22P361206. the second character is a "2" this means the engine is from a 1972 model year car. had the serial number been 20P361206, the second number is a "0" making it a 1970 model year. and so on and so forth from there.

[thebuick]

ok im not seeing anything so ill just have to get it to the shop when I have more time to clean it up more and search. the curiosity has me going nuts.lol Thanks you all

['ol Pinion head]

Originally Posted by thebuick

ok so im going crazy trying to figure out this motor in my car here is the block number next to the water pump [ c ] 473795 YX I checked it 3 times I checked different block ID sites and no luck I was told it is a 400 but im not sure of that or of the yea. Can anyone help me out thank you

The ( before the asm number was only used on production model '71-74 blocks.
I'd bet your YX block is original to the car.

[thebuick]

I do know the car was a 6 cyl from factory but I bought it with this mystery motor transplant already in it

[johnta1]

Use the picture WDCreech posted:



Look for the 'Serial #' next to the timing cover.
Probably dirty/oily there.

This will give you the year of the model car it came in.
The plant designation will help also.
Then you can find out for sure what the engine is.

You could even send that partial VIN to PHS to see what the car was originally.



More than likely it is a 71 to 73 400 cid I would say with the '(' at the front of the EUN.