[D Butler]

I had my 7040273 rebuilt, and we suspect the main body is not correct. What would be a valid pick date for a March build 1970 4 speed Trans Am? Thanks in advance for any help

[70TA-RAIII]

I've got 2 pretty original 70 Trans Ams. They are after your build date so I can't answer specifically but if others chime in you could get a pretty good idea of a correct range.
My 05D car has a 0970 dated carb and my 06B car has a 1270 dated carb.

John

[FASTASSBIRD]

I looked at a 70 locally that had a pick date carb AFTER the build date in March. Seems it’s was 1070 and was a California carb on a car in California that was an unrestored all original driver car. It was a 03C. Always scratched my head but man I bet it was the original carb.


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[FASTASSBIRD]

Originally Posted by 70TA-RAIII

I've got 2 pretty original 70 Trans Ams. They are after your build date so I can't answer specifically but if others chime in you could get a pretty good idea of a correct range.
My 05D car has a 0970 dated carb and my 06B car has a 1270 dated carb.

John

What’s the date code on your heads for the 06B car? I’m researching for a 06E 4 speed Trans Am


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[70TA-RAIII]

06B car heads are D220

05D car heads are D290

It looks like you have a pretty wide range to work with.

John

[unruhjonny]

Originally Posted by 70TA-RAIII

06B car heads are D220

05D car heads are D290

It looks like you have a pretty wide range to work with.

John

/\ did you type that correct?

wait a second...
is this a manual vs auto thing?
I'm curious to know the EUN's - if you're willing to share those...

[70TA-RAIII]

Yes, the earlier car has later heads on it. Both cars are 4-speeds.

I'll check some more numbers tomorrow and see if there's a pattern to this.

John

[FASTASSBIRD]

Originally Posted by 70TA-RAIII

Yes, the earlier car has later heads on it. Both cars are 4-speeds.

I'll check some more numbers tomorrow and see if there's a pattern to this.

John

Honestly, I don’t think I’ve seen a later date code then D22 and D29. My block date code is E200 and the trim tag date is as stated before O6E. Fortunately the block is original but now I gotta piece the date codes for the heads intake and carb to bring it back. Thanks for taking the time to help on this. I wasn’t trying to hijack the thread, but the date code for the carb is also relevant for both. Hope my info on the early car was helpful as well. Found it odd the carb was dated AFTER the trim tag date but I honestly believe it to have been the original to the car.....


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[unruhjonny]

Originally Posted by FASTASSBIRD

Honestly, I don’t think I’ve seen a later date code then D22 and D29. My block date code is E200 and the trim tag date is as stated before O6E. Fortunately the block is original but now I gotta piece the date codes for the heads intake and carb to bring it back. Thanks for taking the time to help on this. I wasn’t trying to hijack the thread, but the date code for the carb is also relevant for both. Hope my info on the early car was helpful as well. Found it odd the carb was dated AFTER the trim tag date but I honestly believe it to have been the original to the car.....

interesting...

I have just started looking at EUN's to try to help see differences between different code engines;
My WT (L78) block which is correct to my 06A Formula has a block cast date of April 30th, and the heads (same castings as L74) are April 22 & April 29.
I can't recall precisely off hand, but I know that one of those two head cast dates are dates that BOTH of my spare #12 heads are...

I feel that the carb pick date is directly tied to EUN and the EUN is also directly tied to casting dates for engine parts - so it's all intertwined...
If I have understood correctly the EUN was assigned once the engine was assembled - chronologically;
So if we establish a couple EUN's with 100% correct/original components such as heads, intake, block and carb with the dates, we can create a progressively smaller and smaller window of correctness...
Right now, I just need to get an understanding of how the EUN numbering was applied;
The 1970-1972 engines I have to look at in my garage look like this: 059---- x 2; 038---- x 2; 028---- x 1

Maybe April 22 & April 29th were the final two dates used for #12 castings! - and maybe as head assemblies made it to engine production floor some older cast heads made it into the back of the pile... ??

Either way, I feel this is ALL relivant, and can be a benefit to the community.

[unruhjonny]

... guys like some of you who are lucky enough to have complete numbers cars don't have to spend even one moment thinking about any of this stuff... but that's ok, I kind of like these little puzzles.

[70TA-RAIII]

My EUN's track my head date codes but not the trim tag dates.

05D car has EUN of 0566620

06B car has EUN of 0554140

Maybe I need to swap engines.

John

[unruhjonny]

hmm...
Well that would lend to explain why the earlier car has later heads!

I wonder if this was a production line issue, where it was pulled aside, and the engine was changed...

Thanks!!

EDIT:

05D = later EUN; earlier carb (April 7th) - which would appear to correspond with the car's build date.
06B = earlier EUN; later carb (May 7th) - which would appear to correspond with the car's build date.

Weird...
I wonder if there was a hold up for 1970 WS motors - that the hold up was carburetors(!?) - and with the back log, earlier built motors (which made it to the back of the pile) were installed later...
This is so neat!

... unless I'm missing something, those motors are 12,480 units apart. that's alot of RAIII GTO's and Firebirds!!

[FASTASSBIRD]

06E car block EUN is 591446


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[FASTASSBIRD]

Also WS Block


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[unruhjonny]

/\ thanks!
So from what's being discussed here, it looks like the head casting date you're looking for would be D290;
I would guess that an intake casting date as close as possible to your block casting date would be correct...
I'll stick my neck out about the intake and suggest something within two weeks after the block cast date should be about bang on...
If that carb info is indicitive of a trend, it appears as though the carb assembly date was possibly getting closer and closer to the car's build date...

[70TA-RAIII]

I could see there being some kind of production line issue with the 05D car.
If I look at the PHS invoice for both cars it shows that the 05D TA shipped on 6-12-70, and the 06B TA shipped on 6-15-70, only 3 days apart!

So the Fisher Body side of it may have started the body and assigned the trim tag of 05D at that time and then for some reason it sat for awhile on the Pontiac side before going down the line and being built into a completed car.

John

Originally Posted by unruhjonny

hmm...
Well that would lend to explain why the earlier car has later heads!

I wonder if this was a production line issue, where it was pulled aside, and the engine was changed...

Thanks!!

EDIT:

05D = later EUN; earlier carb (April 7th) - which would appear to correspond with the car's build date.
06B = earlier EUN; later carb (May 7th) - which would appear to correspond with the car's build date.

Weird...
I wonder if there was a hold up for 1970 WS motors - that the hold up was carburetors(!?) - and with the back log, earlier built motors (which made it to the back of the pile) were installed later...
This is so neat!

... unless I'm missing something, those motors are 12,480 units apart. that's alot of RAIII GTO's and Firebirds!!

[FASTASSBIRD]

eBay YZ block. E280 with EUN number 636037. Bare block so no help on carb or head dates.


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[FASTASSBIRD]

This one will blow your mind, eBay WS block.
Date on block: C090
EUN: 542103
Date on carb: 1270
Heads: D290.
Looks moderately original but if so, man that’s some range......


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[unruhjonny]

Originally Posted by FASTASSBIRD

This one will blow your mind, eBay WS block.
Date on block: C090
EUN: 542103
Date on carb: 1270
Heads: D290.
Looks moderately original but if so, man that’s some range......

I am guessing this one has been assembled together... is it still on eBay?
Maybe the partial vin will elude to the car's build date?

[FASTASSBIRD]

Originally Posted by unruhjonny

I am guessing this one has been assembled together... is it still on eBay?

Maybe the partial vin will elude to the car's build date?

Claims no vin, even has the paint scrapped off where you’d assume it would be. Personally I’m betting it’s a GTO block and the vin is stamped just under the head like the other WS block I have at home.


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