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12/6/2019 7:27:02 PM
Posted: 3/14/2005 7:01:00 PM EST
I recently got my 1967 Firebird running and I started to look into what motor was really in this car. When I bought the car I was told that it's a 400 out of a 1971 (ish) GTO. The car has headers on it and I can't get a mirror up in there to see any numbers on the side of the block, but on the front of the block I see that it's a YC coded block. Does that mean it's a 455 or did they make a YC block 400?
Link Posted: 3/14/2005 7:05:32 PM EST
gimme a minute to dig out my books

Link Posted: 3/14/2005 7:12:56 PM EST
There's a 455 YC in '71 and a 350 YC in '74.

look for the stamped VIN on the front right of the block, just to the passenger side of the timing cover. First digit should be '2' for a POntiac motor, and the next digit is the year (for post '67 engines)
Link Posted: 3/14/2005 7:14:34 PM EST

Originally Posted By rayra:
There's a 455 YC in '71 and a 350 YC in '74.

look for the stamped VIN on the front right of the block, just to the passenger side of the timing cover. First digit should be '2' for a POntiac motor, and the next digit is the year (for post '67 engines)



I'm reading....
017911
YC

Maybe it's not a Pontiac motor?
Link Posted: 3/14/2005 8:03:33 PM EST

Originally Posted By Blue84S10:

Originally Posted By rayra:
There's a 455 YC in '71 and a 350 YC in '74.

look for the stamped VIN on the front right of the block, just to the passenger side of the timing cover. First digit should be '2' for a POntiac motor, and the next digit is the year (for post '67 engines)



I'm reading....
017911
YC

Maybe it's not a Pontiac motor?



Post a pic of your motor
Link Posted: 3/14/2005 8:26:08 PM EST

Originally Posted By Blue84S10:

Originally Posted By rayra:
There's a 455 YC in '71 and a 350 YC in '74.

look for the stamped VIN on the front right of the block, just to the passenger side of the timing cover. First digit should be '2' for a POntiac motor, and the next digit is the year (for post '67 engines)



I'm reading....
017911
YC

Maybe it's not a Pontiac motor?

According to my books, that's just a production serial number for the motor - #17,911.

There should be another number, whose third digit is a Letter (for Manf Plant). The 2nd digit in that number is the year.

This page details it
Link Posted: 3/14/2005 8:56:31 PM EST
84S10 -

You can find the year of the engine from the casting dates on the block and heads. On the block, the code is on the pad next to the distributor. On the heads, the codes are near the area of the exhaust manifolds. The heads will be easier to see, but they may not be original to the engine.

Code breakdown is as follows: Letter - two digits - one digit. The letter indicates the month, the two digits indicate the day, and the last digit is the year. This continued through the last 400ci T/As. Example B099, would be Feb. 9, 1969.

Once you determine the year, then look up the block code. You can also look up the head code which is two numbers, or a number and letter code on the center exhaust ports. That may verify if those are the heads for that engine.

One last thing is the block part number which is also near the distributor. If all else fails, you may be able to reference that (though it usually never comes to that).
Link Posted: 3/15/2005 4:44:40 PM EST

Originally Posted By madmedic:
Post a pic of your motor


I can't read anything near the distributor, it's too filthy. I should have pressure washed everything before ashaming myself and posting this picture here.


Link Posted: 3/15/2005 5:37:59 PM EST
Here's another link that shows where the cast dates, serial numbers, codes, and part numbers are located. It's several pages.

Year One

Hey, don't worry about the pic. You've got a '67 bird and a place to start. Lots of cars out there in shows and for sale that looked worse than that at one time.

Be sure to let us know what engine it is when you figure it out.
Link Posted: 3/15/2005 6:19:54 PM EST
Do I have to pull the distributor out to find any numbers back there?
Link Posted: 3/15/2005 6:39:12 PM EST

Originally Posted By Blue84S10:
Do I have to pull the distributor out to find any numbers back there?



No, you shouldn't. The numbers are probably covered with years of gunk, so a pressure washer (cover dist), or some cans of brake clean and a rag should do it. It's tight back there, so you may want to use a mirror and shine a flashlight off it to see the numbers.

I really think if you get under the car, you could see any displacement numbers, even with headers on the car. 455s had the numbers, 400s and 350s a couple of years later.
Link Posted: 3/15/2005 6:39:35 PM EST
That's a picture of a Pontiac motor.
Link Posted: 3/15/2005 6:44:12 PM EST
I guess tomorrow I'll have to make sure I get home from work on time while there's still some daylight out and I'll crawl under it and see if I can spot any numbers. Sure would be cool if it was a 455
Link Posted: 3/15/2005 6:45:55 PM EST

Originally Posted By Blue84S10:

Originally Posted By madmedic:
Post a pic of your motor


I can't read anything near the distributor, it's too filthy. I should have pressure washed everything before ashaming myself and posting this picture here.

www.regionofdoomforum.com/Upload/userfiles/blue84s10/karl%20work%20013.jpg



It is definitely a Pontiac motor...so thats a start.
Now you gotta find those markings.

Hey...with the YC code, maybe someone swapped a 71 455 into it at some point...then again, it could be a 74 350.

I bought an 81 Firebird project car once that was supposed to have a 400 in it that came out of a late 70s Catalina (or so the previous owner thought)...but it turned out to be a Ram Air III !!!
Link Posted: 3/15/2005 6:46:43 PM EST
That's what you get for going with a brand that doesn't have official small or big blocks.
Link Posted: 3/15/2005 6:47:32 PM EST
I hope it's a "big block" Pontiac!
Link Posted: 3/15/2005 7:00:03 PM EST

Originally Posted By madmedic:
I bought an 81 Firebird project car once that was supposed to have a 400 in it that came out of a late 70s Catalina (or so the previous owner thought)...but it turned out to be a Ram Air III !!!



I had an '81 Turbo Trans Am that when the turbo blew and ate the motor I yanked it and put a TPI Corvette motor in it. Them '81 TA's were a whore to work on.
Link Posted: 3/15/2005 7:04:25 PM EST
[Last Edit: 3/15/2005 7:05:15 PM EST by olds442tyguy]
The turbo TA's of that era were a horrible mistake by GM. Valve burning, piston raosting, ring frying, rod throwers. Carburetors and turbos are not the best pairing, but when they chose not to use an intercooler, they sealed their fate.
ETA: I wouldn't mind owning an 89 TTA though.
Link Posted: 3/15/2005 7:12:22 PM EST

Originally Posted By olds442tyguy:
The turbo TA's of that era were a horrible mistake by GM. Valve burning, piston raosting, ring frying, rod throwers. Carburetors and turbos are not the best pairing, but when they chose not to use an intercooler, they sealed their fate.
ETA: I wouldn't mind owning an 89 TTA though.

The original Turbo T/As were brought to us by the same geniuses that brought us the B-O-P Diesels. Damn things didn't even make decent boat anchors.
Link Posted: 3/16/2005 3:45:31 AM EST
I had a 81 turbo as well.. when the seals went it looked like the space shuttle takeing off! It has been a long time since I've seen a motor without a lot of crap haning off of it. I miss my Goat. Heck I miss my Grand Prix.
Link Posted: 3/16/2005 4:12:47 AM EST
[Last Edit: 3/16/2005 4:15:18 AM EST by darwindog]
YC could be a 455 or a 400. I think the 455's were mid compression engines (between the Ram airs and the "niormal" engines). The site I ususally reference is down:
WWW.CLASSICALPINTIAC.COM

But this one has the engine codes, just not the compression for each engine:
www.pontiacpower.org/engine.htm

I've got a YS block in my TA. 10:1 compression and slightly different exhaust manifolds than the RA III/IV versions but still good flow.

And by no means use YearOne or Classic industries for your parts needs. these guys deal only in Poncho and are a private outfit. They even warehouse original parts if repros aren't being made.
www.amesperf.com
Link Posted: 3/16/2005 4:23:46 AM EST

Originally Posted By darwindog:
And by no means use YearOne or Classic industries for your parts needs. these guys deal only in Poncho and are a private outfit. They even warehouse original parts if repros aren't being made.
www.amesperf.com

Is that really what you mean?
Link Posted: 3/16/2005 8:28:38 AM EST
I think year one got me a nos aluminum piece that goes on the front of the engine, the water pump bolts to it. Great place and I loved buying a brand new something that was made in the early 70s.

Course I just stuck a 455 in a 76 catalina. I need to get something more acceptable, and with a stickshift, to drop the engine in since the car rusted away and twisted on me. Then again that boat was a fun sleeper.

One thing I have learned about old cars is even when the car was original to a family the person selling it may not have known what dad or a brother had done on the side.

So check all the numbers and enjoy.
Link Posted: 3/16/2005 10:49:00 AM EST

Originally Posted By DzlBenz:
........ that brought us the B-O-P Diesels. Damn things didn't even make decent boat anchors.


Actually, the 350 Olds diesel block is extremely strong and easy to convert to gas. The only stronger factory Olds block was the NASCAR block. Too bad the NASCAR block runs in the thousands and is impossible to find.
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