# 400 Engine Block Numbers



## chemnick (Nov 16, 2013)

Here's one for you gurus. Some time ago (about 1996) I purchased a '67 GTO project car and have had it tucked away until recently. While the body is out for blasting, I'm going thru the rest and have come up with mixed info from local sources regarding the engine. Obviously it is not original. It is a WS code block with a casting date code of H269. The heads are #12 with a casting date code of H079. Seems reasonable so far. Now the unusual stuff. The casting number of the block is 9799915. The numbers lists I have found on the web and in my books tell me it could be a RA III or in some cases a RA IV. However, the last digit of the casting number (5) is a stamp and not a part of the mold. It almost looks like it may have been ground down before it was stamped. I have yet to pull the pan to check to see if it has 4 bolt mains or not, but that will be soon. I'd be interested to hear any comments you might have on any aspect of the subject. Thanks for your time.


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## geeteeohguy (Feb 2, 2008)

The heads and block are 1970 Ram Air III pieces, at least. I have a set of #12 heads dated the same as yours that I got from the original owner of a 1970 Ram Air III Firebird. The #12 heads were used on all the ram air III cars, including Judges. Not a RAIV expert, but if it were a IV, you'd have different heads, round ports. What you have is an excellent block and heads to build into a stout combination, providing you used dished pistons so you can operate on pump gas. #12 heads are about the best stock D-port head there is. Good luck with your project.


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## chemnick (Nov 16, 2013)

Thank you for the reply. I will be pulling the pan today or tomorrow. I'm still a little curious about the last number being stamped. I am expecting to find 4 bolt mains..................


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## 05GTO (Oct 6, 2004)

chemnick said:


> Thank you for the reply. I will be pulling the pan today or tomorrow. I'm still a little curious about the last number being stamped. I am expecting to find 4 bolt mains..................


I don't remember if the reason for grinding off the 4 and stamping with a 5 was for early production Ram Air IV engines or if they ran out of Ram Air IV blocks (979991) and modified the III blocks until they cast new blocks. But I have years ago ran across information pertaining to this topic. That block is very rare and a couple of things to look for if you take the engine apart would be 1.65 rockers and the Ram Air IV Cam (9794041).

Welcome to the forum and if you get a chance post a few pictures if your 67.


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## chemnick (Nov 16, 2013)

Been busy on the project. I will check rockers and cam, hope I can find GM numbers on the cam from the front when I replace the timing chain/gears (there is a little more slack in the chain than I like, and it's not a double roller, but it does have all steel gears. I also have no idea exactly how to identify 1.65 rockers, but I'll look. Form the sounds I'm beginning to wonder how an engine like this ended up tucked away in a barn in a '67 post coupe up in Maine but it's OK with me. Kinda sorry I let it sit for 15+ years before I got to it. Anyway, I've never attached pics, but even though my '67 is down to bear steel right now, I'll try it. I'll also try to get some clear pics of the engine, numbers, etc. Thanks again for the info and interest. HOLD THE PHONE ON THAT...............I can't get the "insert image" icon to work (almost lost all this text and I type slower than death).


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## chemnick (Nov 16, 2013)

I think I've got it figured out. I'll try to post a pic of the block casting numbers. Also, from this and also another 400 I have kicking around I ended up with two 8-hole water pumps which have very different impellers. The one with the short and straighter impellers was in the engine I have been writing about. It will be on the right and had one diverter plate behind it. The one on the left is from a different engine. That one was found to have two diverter plates (as expected).


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## BearGFR (Aug 25, 2008)

What is the 2-character stamp on the passenger side front of the block, just below the cylinder head? Also, what is the block date code? (4-characters on top rear, near the distributor hole. One alpha followed by three (3) numerics.)

Bear


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## chemnick (Nov 16, 2013)

Block code is WS. Date is H269. Today I confirmed it has a 9795480 (nodular) crank.


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## chemnick (Nov 16, 2013)

Heads are #12, date is H079 (on both).


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## BearGFR (Aug 25, 2008)

Strange.... WS along with the date code (August 26, 1969) and the heads (#12, August 7, 1969) all match up for RA III. However, The ground and re-stamped last digit on the block casting number is consistent for how some RA IV's were built. Now I'm really curious to find out which cam you've got. Right now, I'm leaning towards the following explanation:
We already know that RA III and RA IV blocks were identical except for the numbers, and "running short of" RA IV blocks is the explanation commonly given for the re-stampings. However, keep in mind that the factory cared about getting the cars built and not interrupting "the line". They didn't care so much about making everything match perfectly, numbers wise. It's plausible that on this particular engine, the car was supposed to get a RA III but somewhere in the process someone happened to pull the "wrong" block (one that had been re-stamped for a RA IV car) but by the time the error was discovered (if it ever WAS discovered) it was too late in the build process to go back and change it. Or maybe, on that particular day in that particular plant on that particular build sequence, the plant "ran out" of RA III blocks and someone, knowing they were the same, pulled this one instead. I don't know that you'd ever be able to find out for sure.

When you do get around to finding the stamp on the camshaft (assuming it's still the original cam) then I'd expect to find an "H" stamp for a RA III cam. "WS" along with the date code according to some sources say that engine originally came out of a 1970 Firebird, 4-speed, and in some circles was referred to as a "California Ram Air III". Still other sources say it was in an A-body (LeMans, GTO) manual transmission. (Always check multiple sources, there are mistakes out there.) It'd sure be interesting to try reverse lookups on the possible VIN numbers to get more information.

Bear


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## chemnick (Nov 16, 2013)

*More*

I appreciate the possible background ideas. I'm pretty sure the chances I'll find the original cam are almost nil. I think I can safely say that the one bank of original pistons and another with new(er) TRW pistons along with the 10/10 regrind on the crank indicate a rebuild. Why someone would stop just four pistons short of a complete rebuild I'll never know. Also there are what looks like evidence of an aftermarket set of valve springs (see the spring cap or disc colors) unless the factory ones were done this way. The lifters look very recent too. The car is a Freemont build, but a '67 so that has no bearing obviously. Hope the pics come through, you may find them interesting.
Chemnick


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## chemnick (Nov 16, 2013)

*Duhhhhh*

Now the pics...............


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## BearGFR (Aug 25, 2008)

Curiouser and curiouser...

I see different retainers on the exhaust valves, and one bank of replaced pistons along with one bank of original pistons. (The ones with the round circles in the center are original). Just from the photos, I would guess that whoever was last into it was attempting to spend as little money as possible --- so you just might find the original cam after all. I'm also curious to know if the exhaust rockers are the same parts as the intake rockers. I've heard in the past of folks putting 1.65's on the exhaust side only to try to compensate for the D-port heads. Would it be possible for you to check the exhaust pushrods for indications of them having rubbed on the head - and do the pushrod passages in the heads show any signs of having been elongated (top to bottom)?

Bear


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## Red1970GTO (Jun 25, 2011)

*Vin????????????????????????*

:cool As Bear pointed out, the engine block was originally in a GTO (WS Code). It's most likely that someone other than Pontiac ground off the "4" and hand stamped a "5 (and the "5" is not even the correct font)" in its place for some nefarious purpose.

Since its a GTO all you have to do is add "24237" to the partial VIN that is stamped on the block (drop the first "2" that's on the block). Then call PHS and see if he'll tell you if there's a corresponding GTO in his files.


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## geeteeohguy (Feb 2, 2008)

I've worked with and still work with a few old timer ex-GM techs from back in the day. When an engine came in for warranty work, as little was done as possible to get the unit back out the door in order to save warranty costs. It was common to replace one piston, or one rod, or just one valve spring. The fact that this engine has half of its pistons replaced and that they are still std. bore could indicate that the car had warranty work done at some point. The fact that the pistons are not oem muddies this somewhat, however. But, there could have been time constraints and the dealership did what was necessary to get the car back to the customer in a timely manner. Just a thought.


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## chemnick (Nov 16, 2013)

I've taken the short block and heads to the "hospital" for surgery. I will be going by there today. You probably won't believe this, but I DID jot down some numbers from the front of the cam, however in my spotless, very tidy shop (not) and amongst my GTO books, Motor and Chilton manuals, it seems to have slipped away. I do recall that there was a string of one letter and 2 or 3 numbers stamped on the front of the cam and then a second line below it that I only recall had a circled "M", three numbers, followed by a second circled "M" on the end. I'm guessing that you guys will immediately know that as a particular manufacturer's stamp, but I have no idea. I'll get the numbers later today and I will check the pushrods to see if they have and signs of "rubs" from different geometry rockers.
Chemnick


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## chemnick (Nov 16, 2013)

Camshaft has the following stampings in the rear:
130R
(M)B3 8(M)
There are quite a few numbers and letters cast into the cam between the lobes and bearings, but I was not sure if they would be of any value at this time.

FYI: The other motor I have has a casting number of 481988, a date code of I104 (looks like 1104), the large number cast into the block by the distributor is 75, the stamp code is YT and it has 5 tapped holes on each side for the motor mounts.


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## BearGFR (Aug 25, 2008)

The cam stamp we care about will be on the nose of the cam, on the surface next to the bolt hole for the gear. It'll be a single alphabetic character. Sometimes they're very faint and hard to see. If there's not one there, then more than likely it's not a factory Pontiac cam.

Bear


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## chemnick (Nov 16, 2013)

Bear:
Took a pretty good look and wire brushed the nose area and even lightly scraped that end and I find not even a hint of any stamp. The pushrods show no signs of rubbing anywhere, maybe a slight touch where the guides are, but almost nothing. Also, when I wiped off the pushrods (I made sure I chose an intake and an exhaust) to check them out there was a prominent number "48056" in good sized print on both. Does this mean anything to you, such as an aftermarket brand, etc? Can't remember who asked about pics of my '67 but I'm going to attach a few of what she looks like right now (scary).:confused


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## BearGFR (Aug 25, 2008)

No stamp means it's not a Pontiac cam. None of those part numbers trigger anything in my feeble old brain, but maybe someone else will recognize them.

Body work scared me half to death too, but I found out that with (lots of) time and patience, it turned out to be possible.

Hang in there.

Bear


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## chemnick (Nov 16, 2013)

Bear:
I snooped around and managed to find out that the pushrods (by their part number) are TRW, Pontiac V-8, at least many V-8's. Hmmm....TRW pistons, TRW pushrods, TRW cam, perhaps? I really don't know if TRW put out cams, but they seem to do most all engine parts. Guess I'll keep digging. I was glad to check and see that the block on the other motor I have is not the one to stay away from. The tables say that the block casting like mine was used as far back as '71, I think. I'll hang in, you can count on that. While the motor's away I plan on swapping in a 10 bolt 2.73 posi for the single traction rear that's in the chassis now. Never done one in a car before (trucks, yes). Setting the depth of the pinion is what I have to read up on since I'm taking the two pieces out of one housing and into the other. Just want to be sure because nothing busts my stones more than a differential that howls all the time, except maybe a rod knocking.......................
Chemnick


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## Tin Indian 1967 (Jun 29, 2014)

chemnick said:


> I think I've got it figured out. I'll try to post a pic of the block casting numbers. Also, from this and also another 400 I have kicking around I ended up with two 8-hole water pumps which have very different impellers. The one with the short and straighter impellers was in the engine I have been writing about. It will be on the right and had one diverter plate behind it. The one on the left is from a different engine. That one was found to have two diverter plates (as expected).


I have the same casting #s on a 70 400 i just purchased freshly done 30 over with a muncie 4 speed for $1200 but it has #12 heads, the 5 is stamped . Any info you find out about this would be greatly appreciated. New member,


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## Tin Indian 1967 (Jun 29, 2014)

Red1970GTO said:


> :cool As Bear pointed out, the engine block was originally in a GTO (WS Code). It's most likely that someone other than Pontiac ground off the "4" and hand stamped a "5 (and the "5" is not even the correct font)" in its place for some nefarious purpose.
> 
> Since its a GTO all you have to do is add "24237" to the partial VIN that is stamped on the block (drop the first "2" that's on the block). Then call PHS and see if he'll tell you if there's a corresponding GTO in his files.


I have the same stamped 5 with # 12 heads also, I'm new trying to find out what engine I just purchased


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## Doug Willinger (Nov 6, 2017)

The WS 400 numbers matching block on my 1970 Trans Am (that I have owned since 1979) is one of these!

It has an early January 1970 casting date, and the car was assembled at the Ohio GM facility in February 1970. It had the number 12 heads, and has the 4 bolt main caps.

Like yours only the last number was machined away and replaced with a stamp, and the "1" is extra large, just like yours, however the 3rd "9" on mine is hard to read.

But what Ram Air IV cars were being then assembled there. I though that the Ram Air IV 1970 Trans Ams were all July production.

What is the deal with all of these "service replacement" blocks advertised on the internet that have the entire 9799914 machined away and the entire 9799915 stamped?


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## Shake-N-Bake (Jun 16, 2015)

Doug Willinger said:


> The WS 400 numbers matching block on my 1970 Trans Am (that I have owned since 1979) is one of these!
> 
> It has an early January 1970 casting date, and the car was assembled at the Ohio GM facility in February 1970. It had the number 12 heads, and has the 4 bolt main caps.
> 
> ...


The 1970 model year has it's fair share of confusion related to the 400 cubic inch engine codes. I think it's easier to make sense of things by looking at the 2 letter codes for the various engine options. (WT, WS, WW etc). These can be thought of as a "recipe" for building the engine. For 1970, there were at least 11 different recipes for the 400 engine alone. 

I believe there was one engine assembly plant that supplied assembled engines to all the various Pontiac final assembly plants. The workers at the engine assembly plant built the engines per the recipe for each 2 letter code. So, for example a 1970 WW code (RA IV) would require a 4 bolt block, Armasteel crank, forged pistons, 041 cam, alum intake and several other items specific to that application. 1970 WS calls for 4 bolt block, nodular crank, cast pistons, different cam etc. 1970 WT calls for 2 bolt block, nodular crank, cast pistons etc...

But wait....in 1970, there was a asterisk on the recipe sheet that said WT GTO engines get a 4 bolt block but no mention of anything special for WT Firebird or LeMans engines. So, how was the engine plant to know if the WT engine they were building was for a GTO? As best as I can tell....there was no way for them to know what car that engine would end up in. 

All 1970 400 cubic inch blocks were cast at the foundry using the 9799914 mold. Most were machined and fitted with 2 bolt caps....some were machined and fitted with 4 bolt caps. Some others were machined a little differently and had 4 bolt caps and these were for the RA IV recipe. Those blocks need to be identified so the cast "4" was ground off and then stamped with a "5". 

To assemble a WW engine, the worker should use the 9799915 block. WS engines should get a 9799914 block with 4 bolt mains. YS would get 9799914 block with 2 bolt mains. WT engines would be a wild card and the likely source of much of this confusion we experience today. Since the engine assembly worker would have no clue if that WT engine was for a GTO or not, he/she might have used a 4 bolt block in case that engine ended up in a GTO. If this practice did occur, then one could expect the supply of 4 bolt 9799914 blocks to be consumed very quickly. This might be why we see documented examples of 9799915 blocks used for RA III applications such as your WS engine. The 9799915 block may have been suitable for RA III applications so that may be why we see them in some cars.

Service replacement blocks are current castings that are machined for the specific application for the current year as well as for previous model years. A service replacement block cast in 1970 for use in a 1968 Ram Air application would have the 9914 ground off and stamped with 2506. Some blocks had all the numbers ground and restamped...it varied. A service replacement block cast in 1971 for a RA IV application would start as a 481988 block and then have all numbers ground and stamped 9799915 for 1970 or 9792506 for 1969. 

Sent from my XT1585 using Tapatalk


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## Doug Willinger (Nov 6, 2017)

Something else that I observed more recently, the "S" of the "WS" is faintly stamped and almost invisible, while the "W" is stamped more normally.

In conjunction with the factory 9799914 to 9799915 block casting modification, it can almost be taken as a suggestion that this block wanted to be a "WW"- which is the Ram Air IV manual code.

Am now doing a rebuild of this as a "Ram Air III/IV" with 4" stroke, 434.95 cid with 1973 service replacement 614 heads.


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## Doug Willinger (Nov 6, 2017)

Has anyone found a 1970 9799915 block with a "YZ" stamp?

Or, were all of these Ram Air III/IV hybrids the "WS" code?


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## PontiacJim (Dec 29, 2012)

Doug Willinger said:


> Has anyone found a 1970 9799915 block with a "YZ" stamp?
> 
> Or, were all of these Ram Air III/IV hybrids the "WS" code?


The YZ stamp is for the GTO 366HP RAIII or Firebird/Trans-Am 345HP RA III. If the "4" were ground off and stamped with a "5" indicating a RA IV, I would be suspect of a fake - and I found a blog stating exactly this same scenario with a WS stamped block. The Pontiac performance book by Pete McCarthy lists the production numbers of the RA III/IV GTO's & Judge's and Formula's & Trans-Am's. I might also assume that if it were originally in a car that the VIN numbers stamped on the block might be traceable through PHS to confirm the car and the correct engine.

Don't know what you are calling a "hybrid"? The 1970 RA III/IV engines were built off of a 4-bolt main 400CI block which would be the common denominator, along with a few other things like cast connecting rods. I have read, but not confirmed personally, that the RAIV had thicker main webbing?


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## Shake-N-Bake (Jun 16, 2015)

I wish I could remember for certain.....but I have owned several 4 bolt 400 ci blocks, maybe 4 or 5. Wish I would have paid more attention to stampings or cast numbers but that stuff wasn't really of interest to us back then. We were just interested in building a competitive engine in time for the upcoming weekend drag races. I do remember that one block had no cast number at all.....not ground off, actually missing the number. Later determined it must have been an early 1968 block based in the cast date and other details. Sure wish I kept that block since it would have come in handy later. I did keep a 1970 RA III block that I bought for the #12 heads.....sold it decades later to someone who needed it for his car. That block had the last "4" ground off and a "5" stamped in its place......yet it came from a RA III car. Strange. I have also seen 9799914 blocks with 4 bolt mains and stamped as a standard WT engine. As best as I can remember, all the 400 ci 4 bolt blocks appeared to be exactly the same dimensionally...never noticed any meaningful differences. One block did have reinforcement ribbing in the lifter valley but that was likely a RA V block or the rumored RA IV SD.....never figured out where that block came from. Sold that one to Rick at Purely PMD for use in one of his projects.


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## PontiacJim (Dec 29, 2012)

All the 1970 RA engines had 4 bolt main caps. The 1968-1969 RA III engines were drilled for 4 bolt mains but only had 2 bolt main caps, BUT, the 1969 RA IV did have the 4 bolt main caps. Some non-RA automatic cars got 4 bolt main blocks with 2 bolt caps.

From Pete McCarthy's book on Pontiac's.

The RAV and SD blocks got the extra webbing/support ribs in the lifter valley.


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