69 307 engine block ID question

[69RedCST]

Hi All , I âm currently restoring a 1969 CST Blazer. It had a 307 engine originally. I am looking for a 307 engine block that came out of a 69 Blazer or one that would not show any difference of one that came out of an 69 Blazer. I want to make sure the casting numbers or whatever would show that it could be the same as one that was in it originally. I understand that the serial number would not match . I’m not very knowledgeable about how this stuff works. Can someone direct me on a 2nd grade level. And if there is any for sale. I will buy immediately. Thank you for your time and patience in advance.

[Getter-Done]

There are sites in the links below that have some of that information.

Hope this helps.

Link: https://www.tpocr.com/chevrec.html

Link:https://nastyz28.com/chevy-engine-code-stampings.php

Link: https://outintheshop.com/faq/casting/castings2.html

[geezer#99]

Don’t forget mortec.

Lots of numbers for a 307. You’ll need to match up the date code too.


https://www.mortec.com/castnum.htm

[69RedCST]

Thank you for that information I will definitely keep it. Unfortunately it doesn’t give me the answer I’m looking for. My goal is when I open the hood and I look at the casting code I want to make sure that if the code does decipher what vehicle it was put in that I have one that was for a blazer. If that makes sense….

[geezer#99]

So if you pop open the hood, where is the casting code you’re looking for?

Just trying to figure out your dilemma.

[69RedCST]

Sorry for the confusion. I’m looking to buy an accurate 307 engine for my 69 blazer. I don’t currently have one. I have found some 307 blocks but I want to make 100 percent certain that the one I buy is one that came out of a 69 blazer. I don’t want to buy a 307 engine block that came out of a Camaro or passenger car. I believe the casting or something on the engine will decipher what it came out of

[geezer#99]

The suffix code will.
The stamping on the flat pad at the front of the passenger side head will have that info.

[69RedCST]

I want it period correct (1969) and I want it vehicle correct. If there is such a thing. If not then it’s immaterial but I’ve read all kinds of Different things from, the trucks that had 307s in them don’t have partial vins only the cars did. That they all had vins etc. just want clarification so I want to buy one out of a 69 blazer or make sure there is no way to decipher what it came out of.

[69RedCST]

Is there a list of what suffix codes mean?

[69RedCST]

I found a block on eBay with a suffix code DC.

Then I see an engine I’d
http://media.imctruck.com/

And for 1969 blazer or Truck that suffix code doesn’t exist but if I Google it it says it’s suffix code for a blazer. I’m confused..

[69RedCST]

https://media.lmctruck.com/Catalog_C..._Engine_ID.pdf

Maybe that will show you

[geezer#99]

Originally Posted by 69RedCST

Is there a list of what suffix codes mean?

Not that I’ve seen.
They’re dependent on how the vehicle is equipped. Different for trans, air conditioning, cooling, power steering or brakes. Each variation got a different code.
They all have the first letter the same. You need letter ‘U’.
No vin numbers on the pad at all until 1973 for trucks.

[RustyPile]

Here's a link to a pretty long and comprehensive list of engine codes. I'm sure what you're looking for is on it..

http://camaros.org/pdf/LimeBook.pdf

[69RedCST]

Thanks so much!! That totally answers my questions! Much appreciated! Now to just find a 307 block with code UF,UJ,UM,UN UQ… any idea where and how to find that??

[geezer#99]

How did you determine you had a 307?
What transmission does it have?

[RustyPile]

A good start would be a junk yard cruise...

[nightmare]

So, for the one in my truck (not original and will be replacing) would this be from a car, then?

Don't know why the picture is upside down...

[69RedCST]

That could be from a car or truck. On the picture that’s upside down what is the suffix letters? That will most likely tell you what it’s out of. The casting number is for either a car or truck 69-73.

[nightmare]

Originally Posted by 69RedCST

That could be from a car or truck. On the picture that’s upside down what is the suffix letters? That will most likely tell you what it’s out of. The casting number is for either a car or truck 69-73.

There are no suffix letters. That's all that is on that pad.

[RustyPile]

It's possible that's a service replacement engine..