COPO 9010 Carburetor

[Rowdy Rat]

OK Marlin... Here's one for you (or anyone else out there who knows).

What is the correct carburetor for the LT-1/M-40 application in the 1970 Nova? The 1970
Z-28 specs call for a Holley 780cfm; either 3972120/4490 (GM part number/Holley LIST number) or 3972122/4554 when the car was ordered with NB-2. Is there any evidence of Holley LIST 4800 ever being used (this is listed as a 1971 application)?

Thanks for any feedback you can provide.

Regards,

Stan Falenski

[YENKO DEUCE REGISTRY]

Stan;
To our knowledge the Holleys installed on the a/t Deuces were 4490's. I have not seen any 4800's, nor any 4454's. I don't know what 'NB-2' is. I have a Yenko Deuce article written by Alan Colvin in 1996 where he lists a 4556 as the carb for the a/t LT1's, but I believe that is a California carb.
M

[Chevy454]

Here is what NHRA shows:

Holl 4489-1A/SM, 4454-1A/AUTO, 4555-A/SM 4490-A/AUTO, 1686x1686/1375x1437

This takes in the Camaro and the Corvette, as well as the Nova, but is this info close to being correct?

Now, this is a little off topic, but what carb would have came on a '66 L-79 Nova?

[Rowdy Rat]

Thanks for the information guys!

I said NB-2, but meant NA-9 (my mind is starting to go - at least I got the "N" right). That was the California emissions option I've seen on a few 1970 LT-1 Corvettes. Basically carbon canister, vent line, carb shield, etc.

In any case, thanks again!

Regards,

Stan

[COPO PETE]

On my car, the carb is 3972121. List 4555.
Peter

[Chevy454]

I just cleaned up what the NHRA had listed a little bit:



Did the Nova, Z-28, and Corvette supposedly use the same carb?

[Edited by Chevy454 (12-12-2001 at 11:45 AM).]

[YENKO DEUCE REGISTRY]

To my knowledge the Z28's and Corvette's used different carbs, and the Novas are equivalent to the Z's.
M

[Chevy454]

So, the Z/28 (and Nova) used a different carb than the Corvette. So which carb(s) above is designated for which car? Were the Novas and the Z/28s engine components stamped the same? Do they use the same part numbers on the entire LT-1? (eg. could you tell a '70 Z/28 engine from a '70 COPO Nova engine?)

[YENKO DEUCE REGISTRY]

Rob;
I believe the 4489 and 4454 carbs were specific to the corvette, but were allowed to be run on the Z28's and vice versa for NHRA tech. purposes.

The only way to tell if a particular LT1 that is coded as a CTB (4speed) or CTC (auto) came from a COPO Nova is if a Nova VIN is stamped on the cylinder pad.
M

[Rowdy Rat]

<BLOCKQUOTE><font size="1" face="">quote:</font><HR>To my knowledge the Z28's and Corvette's used different carbs, and the Novas are equivalent to the Z's.<HR></BLOCKQUOTE>

Well, I agree that the Novas and Z-28s would be the same (as you stated, they used the same codes - CTB and CTC). But did the four speed Corvettes use the same carb as the four speed Z-28s and Novas as well? Pete's 4555 seems to indicate that they did.

Rob, I can tell you about the Corvette LT-1s with a bit of certainty as I'm pretty familiar with them (somebody else will have to fill in the blanks on the Camaro/Nova issue). All Corvettes with the LT-1 were 4 speed manual transmission cars for all three years it was offered as an option (1970-72); there were no automatics. In 1970, four engine codes were listed CTU, CTK, CTV, and CTR although the CTR code was not used in production (there is some conjecture that this may have been the code for the automatic, but there is no proof). The CTU, CTK, and CTV Corvette codes used the 4555 carburetor except when NA-9 was ordered. If an LT-1 was ordered with NA-9 (what basically amounted to California emissions) then the 4489 carburetor was substituted along with a carbon canister, vent line, carb heat shield, and a few other items.

No 1970 Corvette that I'm aware of used the 4554 or 4490 in production which makes sense as these were carbs for automatic engines. I'm a bit surprised that the Marlin's research on the Deuces indicates the 4490; I would have expected the 4554 with the M-40 and 4555 with the M-20/21/22 in all but California applications and 4489 (4 speed) and 4490 (auto) when a car received the CA emissions hardware.

Does this sound reasonable or am I way off base on this one? Any second generation Camaro guys - what's the correct carb for a '70
Z-28?

Regards,

Stan

[YENKO DEUCE REGISTRY]

Stan;
I was not aware that the Corvette's used the same 4555 carb, nor did I know that there were no a/t's installed behind an LT1 in a vette.

The issue of the COPO Novas using the 4490 carb is from the various owners of those cars, and can not always been deemed 100% reliable. I will do some additional research on those guys to make sure they are not just quoting 'some book' when they reference their carb's number.
M

[COPO]

My '70 Z-28 4 speed has its original #4555 and the auto should be #4490. These are for non-CA cars.