I have C heads on my '70 455 engine (numbers match VIN). I realize the correct heads should be stamped E.

Take a look at these pictures. IMG_0497.JPG IMG_0498.JPG

1. I'm trying to confirm these are C heads designed for a California car.
2. If true, would I be gaining or losing performance by swaping out for E heads?

Also, any knowledge (or link to info) for A.I.R would be appreciated.

Thanks

 

That's what it looks like to me. The A.I.R. system was removed and plugged.

 

No difference in performance.Maybe Tweed will chime in about those AIR ports.He has info on those.

 

Yup Brian -- Here i am!! Those are indeed "Calif smog" heads. Contrary to the suggestion above that they were smogs and had smog stuff removed and plugged --- these heads look like "factory" smog plugs to me! Yes there is a difference -- factory smog plugs were NOT just standard pipe plugs! These heads perform no differently than any non-smog C head. And in comparison the the E heads that would be correct for your motor --- those C's will perform as well, if not better, than the E's. So the only reason for you to change them would be for you to get the correct E heads on your motor. Depending on the casting dates and stampings on those C's - They could have been off a 67 W-30 which makes them a bit more desirable for us W-30 guys. If you give me the casting dates and the stamped numbers off the front of the pass side head, I can advise you about their origin.
Thanks
T.

 

Thanks for replies.

Tweed, I'll get those numbers later today. I appreciate the background

 

I have a set at the machine shop as we speak. Mine appear to have been of a 1967 turnpike cruiser.

Here is the thread, that might help you figure out what they were from.

https://classicoldsmobile.com/forums...-v-number.html

 

Here is the big block unit number details from 442.com.

http://www.442.com/oldsfaq/ofblk.htm#BB 1965 - 1976 Big Block Block Unit Numbers

Basically it decodes the V******* number on the back of one head.

 

For the sake of demystification, and of faithfulness to primary sources, here is the 1967 engine ID chart.

It shows that your V222232 number (V prefix, no suffix, starts at 200,000) is for a 1967 400CID 2bbl motor, which, as you had discovered, is the Turnpike Cruiser motor.



- Eric

 

Here are the stampings:

• 394 648 - both driver and passenger sides IMG_0501.JPG
• R112777 - on pad at front of passenger side IMG_0502.JPG

** don't look at the spark plugs! I intend to replace them ASAP **

 

So your heads are from a 1967 full size car with a 4bbl 10.25:1 (standard compression) 425.

I'm curious what Tweed has to say about those factory AIR plugs.

- Eric

 

Thanks. What does the 425 indicate?

 

that is the displacement of the engine they were on

 

To rephrase, they came from a 425 cubic inch motor with a 4bbl carburetor and a 10.25:1 compression ratio that was installed in a 1967 full size car (a Delta 88 or a 98, or maybe a Delmont if it was special ordered).

- Eric

 

Well, I didn't have a diamond in the rough. The engine with these heads still screams, though.

The latest info begets the same question posed earlier (#2): Should these heads (from a full sized '67 car) flow similary as stock E heads?

 

As noted, the threads for the A.I.R. ports are not NPT, they are straight threads with an inverted flare seal, just like brake and fuel lines. Dorman products sells the correct plugs, as does Mondello, so I wouldn't necessarily claim that these are "factory" plugs, as the factory cars without A.I.R. simply didn't have the heads drilled.

 

The R code more than likelu puts them from a 425, but could be from a Toro 400? In either case they are not from a 442 but still are probably as good as the "correct" E heads for your motor!

 

Joe -- Only cars with shipping destination to Calif got the AIR equip. They did use the drilled heads on other destination cars with the holes plugged.
All of the 67 W30 cars got the drilled heads but only Calif bound cars got the AIR equip.
Anyway , its my opinion that the C heads in question here are as good or maybe better, performance wise, as the correct E heads for his motor. So unless he is insistent on having the correct E heads on his motor there would be not other reason or need to change them. MOO!
T.

 

The generally group-sourced estimate (ie: the conventional wisdom) says that C heads flow marginally better than E heads, but no Olds heads flow well by modern standards.
Both types should have the same 1.625" exhaust valves and 2.000" intake valves for non-442 and non-Toro applications, or 2.072" intakes for 442 and Toro.

You should see no advantage if you switched to E heads.

- Eric

 

What can you use to plug the smog ports?

The A.I.R. tubes on my Delta are actually in good shape, but not hooked up into the cat, and once I get the classic plates (emissions exempt) the AIR tubes are going bye byes

I have the 7A 0142 casting 1985 smog heads

 

No.

If they were from a Toro, the number would be R 112777 T.

... and the Toro was a 425 .

- Eric

 

Ok - wasnt sure about that ---