Quick thoughts only:
The first 258 of which I have a record is 1971, which means smog emission.
I personally don't like to put smog emission carbs on non-smog emission engines for two reasons:
(1) Recalibrating can be quite difficult and/or pricey.
(2) The 1966 amendment to the Clean Air Act of 1963. The key word is "tampering". The penalty is horrific.
One can possibly get by (2) above if one obliterates ALL identification numbers on the carb (thus it could not be used in a smog emission environment). This is how the racers get by.
As a licensed shop, I have to be cognizant of, and abide by, that law.
Now, before someone posts "my state doesn't do testing before....", remember it is a Federal law. And then remember Civics 101 "the Federal Government is more powerful than the state".
I personally do not see the need, as there are plenty of Zeniths from 270 CID G.M.C.'s and 269 CID I.H.C.'s. Yes, the initial cost is more expensive. But what do you think you will pay for Carter metering rods and vacuum springs?
But regardless of the need, (2) above is the reason I will not help anyone do this for any amount of money. This is true of ALL O.E. carbs for 1968 and newer applications, including the one which started this thread.
So, the quick thoughts in this post will be my only thoughts on the subject.
Jon.
Last edited by carbking; 03/28/2020 12:58 AM.
