70 z smog option

Romney Mawhorter

70½ Z/28 RS, M21, 4.10, 65k/71 Restomod SS396
Feb 21, 2021
48
Southern California
On this site, it shows NB2 as (Calif). I'm supposing that means the smog option.
However on my build sheet on my california car sold in california originally (and always remained) the smog option I can find is called NA9. What is the difference and should I have a 4489 or a 4555 carb on my stick z?
 

COPO

Veteran Member
Lifetime Gold Member
Sep 15, 1999
21,710
Ontario, Canada
The smog system was not an option. All 70 Z28’s got it but a California shipped Camaro would have RPO NA9 on the build sheet. It had basically the same smog system as non California shipped cars exept for a different Holley List 780 cfm carb and additional items such as the carb heat shield, charcoal canister with a mess amount of hoses.
Holley 3972123 List 4489 is the proper carb for your California manual transmission Z28.

The 4489 has a different front fuel bowl, brass block and fuel lines and metering blocks.
See List 4489 https://nastyz28.com/threads/1970-holley-780cfm-list-4489.325448
Carb
3B2CFBDA-BB55-48B4-9E8B-9A61B18FAB4C.jpeg
C19E2DC6-0FDA-4880-A820-524EA5CE9533.jpeg


Charcoal canister
BE52E53A-56A5-4087-83DA-CA793797ACCB.jpeg


See List 4555 on my website https://my1970z28.com/COPO/holley.htm
780%20front%20view.JPG
 
Last edited:

Romney Mawhorter

70½ Z/28 RS, M21, 4.10, 65k/71 Restomod SS396
Feb 21, 2021
48
Southern California
Thank you for all the good information. Where is the vapor separator on the car? I can't tell from your pic. I think that is also called a tcs is it not?

Also if you have, a pic of the carb heat shield.
Thanks. Will work on my car this weekend needed a start.
 

Budz

Veteran Member
Lifetime Gold Member
Mar 17, 2002
3,390
Ashburn, Va USA
The TCS system is a different beast, the vapor separator is not part of it.

Here are some pics of a reproduction NA9 heat shield I bought in 2009 produced by a member here, screen name flowjoe . I don't know if he has any more...maybe try and message him through the "conversation" feature. To be honest, I can't remember why he supplied two gaskets with it (thick & thin)
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