[Gromit]

Quote: "are we talking about buying off the shelf 2 general purpose springs, or is it sold as an accelerator return spring? Universal one or buy one specifically for the C-10 or Quadrajet?"

Yes, you have the right idea; the ones I use are just general purpose "nested" dual springs. (photo attached) Sometimes the kit comes with a mounting bracket that you can put under a convenient bolt that is in about the right spot to give you reasonable tension on the spring at full throttle; and enough to keep the throttle butterfly closed at idle.

If there is too much tension on the spring I would worry about the throttle bushing getting worn so there is a happy medium somewhere that you will know when you feel it.

I have seen these same springs described as Holley springs and Quadrajet springs.. you can google "carburetor dual springs" and see what you get but the type in the photo are usually hanging on a peg in the auto parts aisles.

Oops I just noticed Grumpy was way ahead of me in mentioning the high arc in your fuel supply line.. sorry Grumpy, I didn't see it before I posted.

One other observation I notice your spark plug wires are touching ground or metal in many places and sometimes moving parts. - That may or may not cause an issue - but I would keep that one that looks to be touching your temp gauge wire at least 1/4 inch from the wire.. (maybe I'm paranoid)..