You know, your description of how you have to tap the accelerator pedal to return to true idle RPM's sounds very much like the process of coming off of choke warm-up, where you tap to come down to idle. Is it possible that your choke mechanism could be hanging up the accelerator action? If it were, than it isn't an issue with the spring (other than aesthetics) but rather fixing a mechanical mechanism that is preventing a return to idle. Just a thought.

 

Try using two springs
The big one outside the smaller one
Like the cars and trucks with Quadrajets

 

1st Gen
after reading your message I went back out and looked at my set up, and you could be absolutely correct. Turns out my choke is freewheeling and not connected to anything! there is no electric choke and there is no manual choke setup. The choke is just sitting there and flapping at will. With that being said I have ordered an electric choke for this unit and will be installing it as soon as it stops raining in sunny California. And to Manicmechanic007's point I will take the opportunity to also add the return spring bracket using the rear bolt of the intake to secure it and will be using the dual spring set up to pull back the throttle. And while I am at it I will take a toothbrush and some carb cleaner to get the gunk off of the exterior of the carb. Once this is resolved that will complete my to do list for the drivetrain and I can move on to adjusting my windows and finally get to electrifying my hideaway lights. I will post my results on the return spring and carb issue soon. Thanks again for the words of wisdom.