The Stovebolt Site Forums The Shop Area General Truck Talk I6 '72 emissions (Carb & choke)

Hi everyone, new guy here, love '67 - '72 trucks. So anyway, I bought a '72 shop manual to help me relace the really screwed up carb on my newly-acquired '72 half-ton. The shop manual shows a lot of stuff related to emission control (anti-deiseling solenoid, vacuum advance control circuit switch on tranny, etc, etc), none of which exists on my truck. Were there California & non-California versions of this truck, or do I have a truck with mixed-year components? Here in New Hampshire, emission equipment rules seem to have been sorta elastic with older trucks, but the state is on the verge of tightening the enforcement, & the rule is whatever came on the truck must still be there. Are your eyes glazing over yet? Sorry.

Yes there were difference between CA. emission devises & the other states. The problem is these early parts were left off when repair work was done or purposly remove because they worked better without them. You could improvise a system that would close to original.

My 68 has all the old emissions including smog pump. I have not really observed much difference between CA and the rest of the country for emmissions in the 67-72 series. There may be a difference though. Certainly in later years there were different requirements.

There are some variations in smog components depending if it is an automatic or manual transmission equipped trucks. Also 1/2 ton trucks seemed to have more smog stuff than 3/4 or 1 ton trucks.

Check out the message boards at www.67-72chevytrucks.com if you have not already. Someone may be able to help you out.