# Reverse vehicle trace by stamped block numbers



## chemnick (Nov 16, 2013)

From prior posts I have been able to establish that the engine in my '67 GTO is not original. In reading my restoration books and now having the front of the block cleaned up so I can see the stamped numbers at the lower front next to the timing cover, it would seem to me that together with the "242" beginning of the VIN number if the records existed somewhere one could find out what vehicle the engine came from. I have dealt with PHS for two GTOs I have owned but it seems to me that they figure the stats going from the VIN number (the opposite direction). I know now that I have a 1970 RA III motor and that based on the casting dates it is likely the #12 heads are the ones that came on it. As stated here before the over-stamp of the last block casting digit (to make it read: 9791115- can't tell what the last digit originally was) still is not clear, but I was told here that it was likely a rare block. As I have continued further into the cleanup and inspection I found more interesting stuff. I can now see that on the deck directly below the center of each cylinder there is a capital letter stamp. There are some that are the same, some not and no sequence of any kind. Weird or not weird? Marking deck clearance or piston height at TDC perhaps. The bore is standard, but the pistons (flat top)have been out I'm pretty sure because the rods and caps are marked with prick punch dots and the crank is marked M10 R10. I have been kind of struggling with the decision of whether or not to use this engine in my '67 restoration because it is clearly not going to be a matching numbers or a show winner and I do have a '75 400 motor with '67 061 heads that I could freshen up for it to have. Once again I must ask 'what do ya think?' All (serious)opinions appreciated. HAPPY NEW YEAR!!!!!


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## Instg8ter (Sep 28, 2010)

according to Wallace racing a 400 RA III for 1970 would be casting #9799914* and would be drilled and tapped for 4-bolt main caps.


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## chemnick (Nov 16, 2013)

Yes, it does have 4 bolt mains for sure. Should have mentioned that. Still can't figure the stamp. Don't know why someone would over-stamp the casted 4 to a 5, unless maybe it was a transition block and originally had round port heads. The provisions for a windage tray were there, but no tray, but I got one from another forum member and bought the new (correct) dipstick tubes. I was just about to start thinking about putting on the new head gaskets and buttoning up things and give it a fresh coat of paint when I noticed there was some pitting in one of the cylinder walls, now I'll have to think about boring the block, etc. A complete rebuild wasn't in the budget, but you know how that goes............


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## Instg8ter (Sep 28, 2010)

if it is a RA III (4,844 production) and you have another motor i would probably build the other and sell that block to someone doing a correct resto on a 70'. Problem is with the re-stamp, i have seen another motor for sale recently that was re-stamped, and it raised questions about its authenticity.


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## chemnick (Nov 16, 2013)

*Just noticed*

Hey g8ter:

Just noticed your poncho is a post coupe..............so's my '67 GTO. Two years back I sold my '66 GTO which was also a post coupe. They go just as fast a hard top, maybe faster!!


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## Red1970GTO (Jun 25, 2011)

*Block*

Sorry, but I'm coming into this discussion at a late stage... When talking about a particular block and which Make and model automobile it was originally installed in the first two things you need to know are the *Block Casting Number *(which you have) and the *Block Casting Date *(which you also have). These facts will tell you the year of the vehicle the Block originally came in (and in some cases will rule out specific models). The partial or "Confidential" *Vehicle Identification Number* that is stamped on the block has a model year indicator which should correspond to the Casting Date Code information.

*NOTE*: The modified Block Casting Number of 979991(5) was only used on the *Ram Air IV *engines. This is where the Pontiac Engine Assembly Plant took a select 9799914 block and modified it for use as a Ram Air IV Block by grinding off the "4" and hand stamping a "5" in its place. Please note that counterfeiters have been know to grind off the "4" in an effort to fake a Ram Air IV Block. Pontiac Engine Blocks also have a "Use Code" stamped on them. The *factory Ram Air IV Blocks* have a "Use Code" of either "*WW* (for a 4 Speed Manual Transmission)" or a "*XP *(for a TH400 Transmission)." However, I understand that these Ram Air IV "Use Codes" can be also be faked by re-stamping. Your "Use Code" of "*WS* (Ram Air III 400 with an Automatic)" could indicate that at some point someone other than factory personnel messed with your Block Casting Number.

Your *Block Casting Date* (H269) should indicate a very early 1970 Model Year Automobile (with an Assembly Date for the Automobile of mid September, 1969 -- during the 1970 Model Year).

So you have a 1970 model year Ram Air III engine (originally) backed up by a TH400 Transmission.

In order to extrapolate a full Vehicle Identification Number from just the block numbers you'll need to make a guess at what model Pontiac the engine originally came in. Because the Ram Air III was available on only the GTO or the Firebird Trans Am you only have those two possible Vehicle identification Number prefixs to select from. Therefore, the full Vehicle Identification Number for your engine would be either *242370*X123456 (for a GTO) or *22887*X123456 (for a Trans Am). Furthermore, since the Trans Ams were built at only the Norwood (Plant Code "N") or Van Nuys (Plant Code "L") Final Assembly Plants you can cut down your guessing: If your Partial VIN shows an "N" or a "L" as the seventh digit then the block obviously came out of a Trans Am. If the Partial VIN shows any other code letter (A, B, G, P, R, Z) that would make it a GTO.

I didn't see a Partial VIN listed in your prior posts... That data would be interesting: Do you care to share it with us?


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## Instg8ter (Sep 28, 2010)

The post coupes are listed at 20# lighter than the hardtop and the coupe is a more ridged platform so with the same motor it would have a slight advantage.


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## BearGFR (Aug 25, 2008)

Red1970GTO said:


> *NOTE*: The modified Block Casting Number of 979991(5) was only used on the *Ram Air IV *engines. This is where the Pontiac Engine Assembly Plant took a select 9799914 block and modified it for use as a Ram Air IV Block by grinding off the "4" and hand stamping a "5" in its place. Please note that counterfeiters have been know to grind off the "4" in an effort to fake a Ram Air IV Block. Pontiac Engine Blocks also have a "Use Code" stamped on them. The *factory Ram Air IV Blocks* have a "Use Code" of either "*WW* (for a 4 Speed Manual Transmission)" or a "*XP *(for a TH400 Transmission)."


...or XN if the engine was originally in a Firebird...

I don't recall seeing if you posted the 2-character code anywhere, but if it's one of those then you might just have yourself a RA-IV block there. It would have originally had round port heads (casting number 614 in 1970, casting number 722 in 1969). The cam would have had a "T" stamp on the end (behind the cam gear) and part number 9794041.

One possible way to confirm would be to re-construct the possible vehicle VIN, using the VIN serial number off the block (drop the leading "2" and use the just last 8 characters from the engine VIN stamp) and pre-fixing it with the following:

24237 (GTO hardtop)
24267 (GTO convertible)
22387 (Firebird)
22487 (Esprit)
22687 (Formula)
22887 (Trans Am) 

..then seeing if you can get a "hit" on any of these full possible VIN's from PHS.

If the block is a legit RA IV, you ought to be able to find out that way.

Bear


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## geeteeohguy (Feb 2, 2008)

I'll add: if the '75 400 is a '577' block, I'd find another to build....like a '74 and earlier. The '75-up blocks are much weaker than the older blocks, and not very desirable. You could sell your '70 block to a restorer and get more than enough cash to go a long way towards the build of another early 400 block. As far as the post coupes go, in my experience, they are much more rigid than the hardtops, and tend to feel much more solid, as well as being pretty much rattle and wind noise free. They have a lot more strength than the hardtop cars....just don't look as 'cool' with all the windows down.


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## chemnick (Nov 16, 2013)

OK guys. Here is what I have to this point in additional info: The number stamped in the block way down on the right side of the section which is machined down for the timing cover (the entire number) is "20B110997" part of which I believe I have learned as a Baltimore assembly ID. From the info given by Bear either there was no post coupe or one of the numbers was accidentally omitted. I have to say that there continues to be a remarkable amount of possibilities for the history of this engine. Maybe an old retired fart like me should write a book (with all the proper acknowledgments given, of course). My apologies for having this same discussions going under two different subject lines, but the story just seems to grow and grow. Certainly it is a possibility that over the course of 44 years someone, for some reason, swapped from round port to D port heads. More to come, I'm sure.
Chemnick


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## BearGFR (Aug 25, 2008)

So, possible VIN:
242370B110997 (GTO hardtop)
242670B110997 (GTO convertible)
226870B110997 (Firebird Formula hardtop)
228870B110997 (Firebird Transam Hardtop)
226670B110997 (Firebird Formula Convertible)
228670B110997 (Firebird TransAm convertible)

That sequence is just my "guess" progressing from most likely to least likely.

Bear


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## tiger13 (May 4, 2012)

Not to intrude into a tread, but what would a good running 1970 RA III engine be worth? I have one sitting in the corner of the shop I was toying with the idea of putting into my Le Mans to replace the 326 that is in it now when the restoration is done. I got the 326 running great, and it is the original engine, but that lump under the blanket in the corner keeps whispering to me.


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