Recently purchased 72 GP
 

Picked this up about a month ago. The story is that it's a two-owner car, with a brother-in law buying it from the family after the original owner passed away. He had the car since 1982. Nice original interior. Repainted back in the 80s, so it will need some TLC. Tune up and brake work so far. It seems to be running really well at this point. I've loved these cars since I was 13 years old, and my parents bought one brand new. My dad routinely traded cars every 3 years, but mom wouldn't let him get rid of her 72. She managed to keep him from trading it until 1980. I'm hoping to hang onto this one for a while. I was a little worried about the numbers. The car was built in April of 72. When I scraped off the grease and checked the engine block it has a Y3 code instead of YS. I put it on the ramps and checked next to the timing cover and there it was, the matching VIN stamped into the block. Heads are correct 72 heads. I'll have to get the PHS on the car to make sure, but it appears that this has a numbers matching engine even though it has a 1973 engine block code. The PHS should verify whether or not it's correct.

great looking GP!!

Does it have 14 or 15 inch wheels?

Y3 is a 1972 engine code also!
(400 4 bbl)

:)

Nice score and that interior looks amazingly preserved

I've been looking all over the internet and the engine chart in my service manual, and I can't find a reference to a Y3 block in 1972, but it does show up for 1973. I'd love to have your source in the event I'm ever questioned about the code? Thanks!

It has 14 inch wheels.

Congrats Chief on the purchase! Looks well taken care of especially that interior...happy motoring!

Engine Code Search

Input Y3 in the engine code section.

:)

agreed.

the Pete McCarthy book doesn't list this, and I just tried the search which was linked, and the results said it was supposed to have a '2263 carb which we know is wrong.

If 1972 was anything like 1973, then the engines which had a unitized distributor would have had a different code from points;
It looks like the McCarthy book doesn't address this (but there are known deficiencies in his book).
1973 is especcially convoluted because for a given engine where the code is shared amongst all
platforms (eg: 400/4bbl/auto) the codes are:
early 1973/points
early 1973/unitized
late 1973/points
late 1973/unitized

Thanks for all the compliments. I am simply amazed by the condition of the interior. It looks like the Y3 engine block in a 72 Pontiac has come up before. Seems to me that the official literature for documentation purposes is simply missing this detail. As we all know they weren't going to shut down production because they ran out of YS blocks on the shelf. Thanks again.

John, your site shows that in 72 y3 code is a 4004bbl. What's weird is it's not in the regular engine code chart, it shows it as an automatic trans but has a 263 carb on it. I thought odd numbered carbs were stick cars. No 72 GP's were stick shift. weird.

Does this have the original carb on it? If so, what's the numbers.

A 7042263 IS a stick carb;
it's a really tough one to find too.

I can't say whether or not it's the original carb. It has a label "remanufactured by Holley." So did they have the original carb remanufactured or just exchange it, I can't say. The number is 7042264. Based on what I can find, it is correct for 1972 YS and ZS codes, but not a Y3 engine code.

I think I fat fingered the carb #, should be 7042264.

I'm not at home, here in Illinois for awhile.
I not sure where I got the info, but probably from a service bulletin or possibly from this website (PY).

:)

Try this link:

Y3 engine code


And this one:

Another Y3 code

:)

The 1972 YS and Y3 400s are virtually identical in every respect. The only difference I can determine is carburetor application. YS used 7042264 while Y3 used 7042274.

The updated version of this book contains an index much like Pete McCarthy had in his book and midyear-1972 codes such as Y3, and 455’s Y4 and Y5 appear in it.

https://www.amazon.com/How-Rebuild-P.../dp/1613255632

/\ hmm, here I have the older version!?
I'd estimate that 90% of the time I use the McCarthy book, it's for the engine code section, so I guess I will have to add this book to my want list!!
Thanks for letting us know this!