Now that I know that I need to run a newer-than-1967 Q jet on my 383, I wanted to get some opinions on which one I should build.

I have two spares. First one is 7040509 and is a 1970 California Chevy carb. I don't know if being a California carb means that it has leaner internal circuits or not.

The other is a '78 truck carb that looks identical to the pre-76 (or '75?) car ones (does not have the black film canister looking thing inside the bowl like the 76-up cars do). I don't know if this is best suited for me or not considering it is from the smog era.

The other option would be for me to buy a 69-74 carb and I can do that if these are not ideal.

What do you think?

I would start by picking the one with the straightest top plate. What will the 383 be used for?

The car is mostly street but I like to take it to the drag strip a few times per year.

Out of those I think the truck carb is the better bet. I have no idea about the calibration on the California unit, but that's right when they started emmisions mods specific to Cali, so it could be a headache. Does the truck carb have the early or late rods?

Does the truck carb have the early or late rods? It has the early rods. Looks identical to say a 1970, inside and out.

I have also thought about finding a 76-78 Q jet becuase of the easilly adjustable APT and possibility of running an electric choke.

68 get a hold of Sean Murphy induction, he is in California. Great with Q-Jets
Gary.

I have several mid 70's truck qjets available for rebuild..send me a pm if interested.