If it needs to be the correct spring then you need a 72 parts book. Otherwise ..... whatever works.
The return spring on Jazebelle lost tention on the trip back from Michigan and wouldn't pull the throttle completely closed. I cut the long end, reformed the hoop and it worked, but the gas peddle required additional effort to push.
I think a double spring is in the near future.
Just wanted to make sure the Green one was the right one. From what I can tell it is. Original part # 3462753, seller lists it fitting 70-71 E body and 72 up B body 440. I always ran a second spring on my old car.