[Baron Von Zeppelin]

Seems like I have heard about different size registers for flywheels before , but I don't remember how the story goes .

Did you ever go through all the date code drills on this new-used engine to ID the block and heads ?

Crankshaft should have more numbers in the casting number than what you posted.
At least 7 digits
After you get all your dates and numbers nailed down , you could post the question in the "Street Section"

[79 Phoenix]

Originally Posted by Baron Von Zeppelin

Seems like I have heard about different size registers for flywheels before , but I don't remember how the story goes .

Did you ever go through all the date code drills on this new-used engine to ID the block and heads ?

Crankshaft should have more numbers in the casting number than what you posted.
At least 7 digits
After you get all your dates and numbers nailed down , you could post the question in the "Street Section"

Unfortunately, I did not check this out before I bought the engine. I assumed it was a 71 engine. Okay, thanks that's helpful. I will look for more numbers... Also I am not that familiar with Pontiac engines. So I am learning.

[Baron Von Zeppelin]

The block code is STAMPED on the flat machined front face of the block.
Location is upper passenger side - where head bolts to block.
A 7 or 8 digit sequence number stamping , then a 2 digit application code.
The 2 digit code is the main ingredient.
For example will look something like this :
07798562
___ YN ___


The block casting date is located near the distributor hole.
It is CAST on the block in raised digits.
It will be 4 digits - with a fake looking screw head on each end.
Will look something like this :
@ B172 @


The head application code is CAST onto the head in bigger raised digits.
Located on top of the two center exhaust outlet ports.
For example :
11 .... or 33 ... or 4X

The head date code is CAST onto the head - on the outside - an inch or so below the valve cover.
It will look exactly like the Block Date Code described above.

You can check these on both your engines.

[Baron Von Zeppelin]

Some pictures to help.

Block ID and partial VIN


Head ID


Head date code
The date code on the block - near distributor hole - will also look like this example.

[Mister Pontiac]

I would say so, yes.

The fact that you have the VIN match on your trans, and the date code falls in line with the car build date gives you extreme confidence that you have the original trans to your car, which would be the Muncie M-13.

Saginaws from that era had the single bolt on the top of the side cover, and they were weaker transmissions, all things being equal.

I don't know what happened to the designs as the later 70's rolled in.

[johnta1]

I fat fingered my response above and changed it to the correct RM code.
1972 also used RM as the code for the M13 Muncie.

[Baron Von Zeppelin]

If you find a Buildsheet in the car , it would have RM coded in the transmission designation box.
M13 also came behind 69 & 70 Ram3 engines and 70 455HO engines.
They are tuff units.

[79 Phoenix]

Originally Posted by Baron Von Zeppelin

If you find a Buildsheet in the car , it would have RM coded in the transmission designation box.
M13 also came behind 69 & 70 Ram3 engines and 70 455HO engines.
They are tuff units.

Yes, RM is in the transmission box on the buildsheet!

[79 Phoenix]

Okay..thanks. i asked him what car it came out of and how long its been out. Also asked him what was done to the engine when it was rebuilt.Here are some more answers ...

1. I have a 1971 Firebird
2. About 2 months
3. I have a list from the previous owner and can only go by his word, he builds firebirds for a living so I took what he said at face value- rings, cam bearings, lifters, camshaft timing chain sprocket, new ignition module, has rebuilt alternator , rebuilt starter. The motor is very clean & ran strong.

[Mister Pontiac]

That would be a fairly 'correct' 71 400 for you (YS would have been from an automatic car, but regardless), $1400 is too high for a core short block, IMO.

If it was a complete engine, especially with the #96 heads, then I would say you might have something.

Personally, I would pass on this one too.

But since you have a lot of other things to do on the car, keep at it. The right engine will pop up. Keep an eye on the classified's here on the forums too. Someone up in your neck of the woods may have just what you need.

[SD455DJ]

Originally Posted by Mister Pontiac

That would be a fairly 'correct' 71 400 for you (YS would have been from an automatic car, but regardless), $1400 is too high for a core short block, IMO.

If it was a complete engine, especially with the #96 heads, then I would say you might have something.

Personally, I would pass on this one too.

But since you have a lot of other things to do on the car, keep at it. The right engine will pop up. Keep an eye on the classified's here on the forums too. Someone up in your neck of the woods may have just what you need.

X2! Way too expensive for a short block! That's the price of a complete engine in my book...carb to pan. Keep looking like Mr. Pontiac said. I paid $400 each for the last '70 400 (complete std. bore) and '73 455 long block (+ .030"). A couple of my cars have 'transplant' engines in them and 99.99% of people never know, look, or ask...even a Pontiac shows. Some have the same year heads so the casting numbers look kosher to the inspectors.

Dennis

[79 Phoenix]

Originally Posted by Mister Pontiac

I would say so, yes.

The fact that you have the VIN match on your trans, and the date code falls in line with the car build date gives you extreme confidence that you have the original trans to your car, which would be the Muncie M-13.

Saginaws from that era had the single bolt on the top of the side cover, and they were weaker transmissions, all things being equal.

I don't know what happened to the designs as the later 70's rolled in.

Where would the VIN numbers and date code be located on the transmission?
I love the M22 whine!! I can't wait to drive this... Hopefully sometime next spring or summer.

[79 Phoenix]

I checked with JASPER and the only way they could get me a rebuilt 400 short or long block is if I sent them one to rebuild... So that not an option.

I got more info from the guy with the short block (link below). He took some pictures for me (below). It is a YS block dated April 21, 1971. The 71 YS block was apparently for 300 HP 400's backed by Turbo 400's. They put them in GTO's, Firebirds and B-body cars. He said he sold the heads #96 off it in years past... Said he thinks it's std bore but couldn't find any markings...
$1400 seems like a lot for a short block without heads... I would also have to assume it needs bored, new pistons and crank turned*(not sure what all that would cost). It's only 2 1/2 hrs away.

https://annapolis.craigslist.org/pts...675788752.html