[Rocky Rotella]

And I should also say, what a great car you have, 392Wrangler!

[392Wrangler]

Thanks, Rocky.
May I say your book is the most informative I have read over the last 30 years. And we thought we knew a lot then. 😆
When we stop learning I guess we are dead.

[Kenth]

To add to Rocky´s info, the #12 heads did not use the oil shields between the retainer and springs. No Ram Air heads did.

[SD455DJ]

Originally Posted by Kenth

To add to Rocky´s info, the #12 heads did not use the oil shields between the retainer and springs. No Ram Air heads did.

I can attest to the #12 heads not having the umbrellas on the valves. My RAIII engine (never torn apart or rebuilt) didn't have them, only the oil drip rails.

Dennis

[keith k]

Very odd that this car has a COX axle. As BVZ pointed out, with the M21, a 3.73 ratio was mandated. It would have been COZ coded since this car was ordered with Safe-T-Track. The fact that the HD Radiator is on the invoice further supports that this car should have had a 3.73, as the heavy duty radiator was another thing that came along with the 3.73 gears, and wasn't typically a customer ordered option. Even though the Performance Axle is not on your invoice, that is not uncommon for the earlier production cars. My guess would be that your car got a different axle than it was supposed to - there was a lot of complexity of "this with that" stuff on these cars, so it wouldn't surprise me if occasionally they didn't get the right parts. But who knows...

Cool car either way, and the Sandalwood interior is a nice match for the Castillian Bronze.

[SD455DJ]

I could be wrong (most likely), but I've always seen "Change Alert" on PHS's of Birds with 3.73's when M-21 was ordered. I don't recall the 3.73 gear with a cost or RPO on PHS's either. I agree with Keith K that the 3.55 COX axle was substituted on the assembly line most likely. It is possible it got swapped out later on...a lot can happen in 50 years.

Regardless, that is one nicely equipped Formula!

Edit: Nope, I'm wrong, just found a few '70 PHS's that have the optional "Axle Perform" code 368 for $10.53 for both M40 & M21. Could it be that "Change Alert" signified they substituted the COX rear for the COZ rear?

Dennis

[Baron Von Zeppelin]

In that case - using your example - it would point to the TAs with just HD Radiator being M21 , and the Perf Axle cars being M20

70 PHS's that have the optional "Axle Perform" code 368 for $10.53

Thinking more about this - isn't that an above average charge for Perf Axle ?
Seems like it was usually just a few dollars for that option , not $10
(for instance compared to 69 & 70 GTO)

Wouldn't a 3.73 axle require a different speedo gear in the transmission on a M20 and M40 , versus 3.31and 3.55 ?

On 64 and 65 GTO you could get M20 or M21 with the 3.90 gears
That particular M20 had a different plant code and invoicing code , due to it having a different speedo gear pre-installed.

Thinking out loud with no files available to investigate

[johnta1]

Edit:

Could it be that "Change Alert" signified they substituted the COX rear for the COZ rear?

I don't think so, at least not just for that specific reason.
My 70 Formula has that 'Change Alert' and I don't know what it was for.
My radio is an AM-FM though and I think it was on PHS as 'AM'?

It had 3sp and 3.55 gear but no locking rear.

I think we had a thread on this quite a few years ago, and no consensus?

[SD455DJ]

John, I should have been more clear, I meant for any deviation from what was originally ordered (any option) vs. what they installed, either they ran out of a particular item to install (like a 3.73 rear end or a lamp missing from a lamp group). I don't know, just my swag at it.

Dennis

[unruhjonny]

Originally Posted by 392Wrangler

According to Rocky Rotella’s book a 70 Formula non RA should have #13 heads on it.
...

If Rocky's book did indeed state this, he was mistaken;
My knee-jerk reaction to your post was that you misunderstood (or misread) Rocky's book.

I realize I am late to the party, but incase further clarification is needed, here is a different way of looking at it;
For 1970 (unlike 1969) Pontiac gave a perk to manual backed 1970 'L78' 400/4bbl engines which were the base engines in both the GTO and Firebird Formula;
That "hot ticket" came in the form of putting the "RAIII" heads on manual backed engines;
I believe that this is mentioned in the 1970 'performance catalog'.

It is correct to suggest that the #12 heads were the "Ram Air III" heads;
It is correct to suggest that the #13 heads were the "non-Ram Air" heads;
These two platforms got the better heads with the non-RA engine - as long as an automatic transmission was not ordered.

The full sized, Bonneville, and Grand Prix were exempt from this "hot ticket" setup;
A manual transmission was not available with the 'L78' for the full sized & Bonneville (the only way to get a m/t behind 400 was to get the 'L65' 400/2bbl);
The GP received a different engine assembly (WX) which used the #13 heads.

[johnta1]

Did you see post 20?

[unruhjonny]

Originally Posted by 392Wrangler

Also this car has the M21 close ratio as is shown on the PHS. But a bulletin on Feb 9th 1970 (Again referring to Rocky’s book says you had to order the 3.73 gears set with that trans, but my PHS does not show Performance axle ratio. It does show safety trak though.
Any thoughts?

I believe that the way it worked is best understood by looking at the options through the lens of a period sales book (of which I have a copy; bought it probably twenty years ago):

#358 4-Speed Close Ratio manual (Safe-T-Track req.)
- 22687 with 37R Axle: $195.36

Later on:

#361 Differential Safe-T-Track (Required with 37R Axle)
- 22387-22487-22687: $42.13

The 'performance axle' option would only show up as a cost option for a Formula w/o option #358, but because your car has option #358, the performance axle was already included.

This is why the close ratio muncie was always (for 1970 & prior) associated with a lower gear set;
Only with the options shuffle for the 1971 model year did the close ratio not always require a lower gear set.

Does that shed some light on to the situation?

You made me do some searching - nice car!!

LINK

[Baron Von Zeppelin]

. The 'performance axle' option would only show up as a cost option for a Formula w/o option #358, but because your car has option #358, the performance axle was already included.

That is pretty much the synopsis I'm trying to evaluate towards the 70 TA's with 3.73
Some with just HD Radiator
Some with HD Rad & Perf Axle

Using this Formula in comparison does seem like it's very possibly an indicator towards the TA's also.
You worded that very well.

Just need enough 3.73 Van Nuy cars with accompanying Bsheets and Invoices to nail that to the TA's.
But it has credibility in context.

[unruhjonny]

Well then, maybe this is key:

Does anyone have a source to spell out what ‘37R’ is?

My Jim Osborn book (reprinted pages from a dealer catalog) doesn’t show it;
My sales book doesn’t show this;
I looked at the copy of an ordering sheet (included with PHS) and it too doesn’t show this.

The ordering sheet doesn’t have a #37 column either…
(does anyone have a full/clear scan of an ordering sheet - because the one I got from PHS in the late 1990’s has the far left edge of the sheet cut off)

I did go look at a VN build sheet - box 37 is I believe the callout for the PS belt - so that's no help...

Maybe Rocky can chime in??

[keith k]

Originally Posted by unruhjonny

The 'performance axle' option would only show up as a cost option for a Formula w/o option #358, but because your car has option #358, the performance axle was already included.

This was a mixed bag in '70. Very early production M21 cars like the subject of this thread seem to have not included the cost for the Performance Axle on the invoice, while later cars did. The extra charge appears on all the M21 Formula invoice copies I have for cars with Norwood VINs beginning 107xxx (late March). See example invoice.

[johnta1]

These designations are what I hate about these sheets.
So many different read-outs, you have RPO, UPC, Sales Codes, then the 'Box' #'s, etc.

If like on the 68 BHC box 37 with R would be the ratio of the rear end, 37S was the 4.33, 37P was 3.90 for the RAI/II's. If still used in 70 possibly for 3.73?
(no 3.90 or 4.33 in 70)

In 1971 they changed how they did some of the codes.
34P for 455 4 bbl, 34U for 455 HO etc.
In 1970 they were 347 for RA IV, 348 for RA III, 345 for L78 400, etc.

So just more mud for the dirty water?

[unruhjonny]

Originally Posted by keith k

This was a mixed bag in '70. ...

interesting.

My sales book has an issue date of February 26 1970 - so it's presumably the first issue for the 1970 model year to contain the "1970+" Firebirds;
I had assumed from how this book reads, that the '37R' axle was included in with the option cost - not an additional required option like it reads for #361.

So it's safe to assume that '37R' = #368 ??

Maybe PMD issued an update of sorts requiring #368 be an added cost option if #358 was ordered?

[johnta1]

Here's what I found:

Code - 348
UPC Code - L74
Available Formula; Standard TA

400 ci Ram Air V8 4BBL (RAM AIR III)
Ram Air III: Not available with 2 Speed Auto Trans (352), Turbo Hydramatic Trans (359), or Mountain Performace Axles (754)


Code - 347
UPC Code - LS1
N/Available Formula; Available TA

400 ci Ram Air V8 4BBL (RAM AIR IV)
Ram Air IV. Not available with Air conditioning (582)

-----------------------------------

Code - 361
UPC Code - G80
Standard - TA

Safe T Track differential
Requires performance axle (368) axle


-----------------------------------

Code - 368
UPC Code - G90 Performance Axle

-----------------------------------

Code - 358
UPC Code - M21
Available Formula; Available TA

Close Ratio 4 Speed Manual Transmission with Hurst Floor Shift
Requires Safe T Track Differential (361).

Formula 400 with Peformance Axle (368) - $195.36
Trans Am with Performance Axle (368) - No Charge


-----------------------------------

[johnta1]

Found this (for GTO but probably similar):
(not sure I have a clearer pic)





(at bottom left)


Axle -Sales Code 37R is 3.07 ; UPC is GX1

[unruhjonny]

I had intended to upload this earlier today, but was having issues with my computer;
Maybe they will shed some light into why early builds don't show the performance axle, while later cars do;
If correct, I would wager a guess that there was some sort of bulletin issued to dealers for the change.