71cutlassdroptop

Trying to decode the following cowl tag
ST70 34487 E 1321 BDY
TR 930 48 48 PNT
12C

From what I can tell it Started out as a Green car with a Green top. The good news is It has a W-25 hood and OAI air cleaner. Was told the car started out as a three speed floor shift car. No motor or trans. But did have original W/Z manifolds. How can I tell if the hood is an original one?

71cutlassdroptop

more pictures

71cutlassdroptop

More pictuers

Allan R

ST 70 - 1970 model production
3 - Oldsmobile Division
44 - Model: 442
87 - Body Style: Holiday coupe
E - Production Plant: Linden NJ??
BDY 1321 - Body number assigned by Fisher Body Works. Not related to VIN
TR 930 - Black themed interior c/w bucket seats
PNT 48 48 - Sherwood Green Upper/Lower
12C - Time/build date at FBW. Car body was assembled in the 3rd week (C) of December (12) of 1969

A factory hood will have a metal substructure and fibreglass top. These are reproduced now so look for aging on the components. The air cleaner and base look original, so the hood likely is too.

droldsmorland

Send us some detailed pix of the hood from above showing any stress cracks and from the underside...particularly the screened in section.
If you see fiberglass age cracking and surface rust on the steel underside chances are it's an original hood...I did not say original to the car. The only way to verify that is with a build sheet showing W25 along with the cars VIN.
The build sheet may help to identify the proposed 3-speed stick status as no 4-speed option would be listed. I don't remember if the RPO 3 speeds were stamped with a vin on 70 or any other year...moot anyway as its MIA.

Allan R

Since the car is not a Lansing build, there's a very good chance the build sheet may be on top of the gas tank. Lots of work to drop it, but if it has the elusive build sheet that's a great bit of documentation.

joe_padavano

The three speed manual trans with Hurst floor shifter was the base equipment in the 442. This was the Dearborn (don't call it a Ford) toploader HD three speed.

WTHIRTY1

In 1970, it would have been the M-14 Muncie 3-speed if it were the heavy duty floor shift. The part number is 3952657 and the code stamped on the trans would have been 'RM.' The parts book lists is at 'F85 V8 3/S S.T. H.D.'

I believe there was also a 3 speed manual trans for non-floor shifts in 1970. The number for that is 346313, and the parts book shows this as the same number for the 66-69 3 speed NON H.D.

joe_padavano

You're right. I geezed on the fact that this was a 1970 car. And yes, the low-po applications still used the Saginaw three speed. If I remember correctly, didn't the full size cars continue to use the Dearborn trans through the 1970 model year?

71cutlassdroptop

Looked at the OAI hood this morning. It does have a steel inner structure. The inner structure looks like it has a lot of surface rust. It also has the holes inside the scoops where it looks like a flapper should go. Will try and get some pictures of the hood tomorrow.

As far as the three speed, it appears that the car was a floor shift without a console. I can't find any mounting brackets or holes where they would of been.

joe_padavano

Which again would have been the base equipment for a 442 that year. The console was an added cost option under RPO D55.

droldsmorland

This is typical evidence of a GM OEM OAI hood. There aren't any "flappers" in the scoop intakes. The only flap would be the one in the air cleaner lid. See the links below. Again some pics would further justify but I'm pretty confident you have an OEM hood. Some pics of the cleaner assembly would help us tell you if it's a 70. The hood and air cleaner assembly are very desirable, so nice score.

The googler search engine works better than the site's engine...

https://classicoldsmobile.com/forums...-w25-hood.html

https://classicoldsmobile.com/forums...tell-real.html

71cutlassdroptop

droldsmorland, what other pictures would help us tell the year of OAI breather

droldsmorland

I'm asking this question as well...Not sure there is a difference. Not the resident 70-72 OAI expert. Are there subtle differences such as the ones observed on the 68 vs 69 OAI cleaners? Not sure if the 70-72 455 OAI differs from the 350 other than the foam height. Make sense if they were the same part. There may be subtitle running changes on the ancillary parts? Someone else can pipe in with that info. If you search the various vendors offering the repro kits the part numbers appear to be the same for 70-72. I don't have the OEM part numbers. Said part numbers will show any running superstitions.

71cutlassdroptop

distributor has the numbers 1112198 242 I think on it. hard to say. Would a manual distributor be different than an auto?

71cutlassdroptop

Here is a picture of the car

71cutlassdroptop

I have been searching for days on how the OAI breather works. Is there a youtube video or something?

joe_padavano

Youtube video? Why?


There's a vacuum actuator connected to manifold vacuum. At idle and part throttle, manifold vacuum is high, so suction in the actuator holds the flapper closed. At wide open throttle, manifold vacuum goes to zero, the actuator rod extends due to the internal spring, and the flapper door opens.

Koda

There's five pieces involved. The oversized bottom sits on the carb like normal. The air filter sits on the oversized bottom. There is a normal sized metal pie pan top that sits on the air filter and has the normal carb bolt holding it all down. At this point, with those three pieces you have an open functioning air cleaner.


The flapper piece is oversized and fits on the bottom's lip, same diameter, and over the pie pan. Now you have a "closed" air cleaner. If you connected vacuum to the flapper, it would open (lift) and become an "open" air cleaner. If you put a sponge gasket and shut the hood, it now is "open" to the draft coming through the hood, thus Outside Air Induction happens. This does not occur until what Joe said.

Koda

Hell, I thought it was heat controlled.

joe_padavano

I was talking about the flapper on the O.A.I. adapter. You are correct that vacuum to the flapper in the snorkel is controlled by that thermostatic switch in the air cleaner bottom. When inlet air is cold, the thermostatic switch directs manifold vacuum to the actuator on the snorkel, which moves the flapper, closing the end of the snorkel and opening the passage to the hot air stove around the exhaust manifold. Once the inlet air is heated, the thermostatic switch closes and blocks vacuum to that actuator. Of course, that actuator is also operated off of manifold vacuum, so if you go to WOT while the thermostatic switch is still open, vacuum goes to zero and the actuator in the snorkel reverts to the cold air position anyway. That's the beauty of using manifold vacuum - at WOT it automatically disables any of these actuators to ensure full airflow to the carb.

71cutlassdroptop

Joe thanks for the help. I was hoping to see one of these work. It sounds like everything is there for the OAI Breather. So it works off of manifold vacuum or the lack of.