A while back I bought dual throttle return springs (chrome) for my big block but I forgot about needing a kickdown return spring. Can someone tell me what the correct spring length should be (unstretched) for use on a kickdown return and where I can get one in chrome if possible?

Can't help you with the length, but I went to local parts store and bought a box of chrome springs of various lengths and diameters. Just went through them until found one that worked.

See pics of the kick down return spring from my 71 RR 383. I hope this is what you are looking for.
Ron

Thanks for the pics Ron. 71 style must be different than earlier versions as what I need should be considerably longer and smaller in diameter. I believe it should span the distance from the throttle pin to the throttle bracket where the ball pivot mounts.

Yup it looks like they changed at some point in 1970. Megaparts has the original non chrome style-
https://www.megapartsusa.com/products.php?cat=687

For reference the pic below shows how the spring is installed. For what year vehicle/engine are you inquiring?
Ron

That spring is a Fairly light spring. If you go with a chrome one be sure it will work.

Maybe John Kunkel can come in on if the tension is really that important.

Here's the measurement on the early spring, the one end is broken off but should still get you in the ballpark.

I believe that's the spring I need. Thanks for the pic and thanks to everyone for your replies.

a little silver chrome paint and nobody would ever know