HELP! Needed H.P. exhaust manifold heat riser spring

I need just need the bi-metallic spring used on a big block H.P. exhaust manifold heat riser. My heat riser assembly is in perfect condition except the tang on the bi-metallic spring is broken off. I don't need/want to buy an entire heat riser rebuild kit just to get that spring. Many times people remove the heat riser assembly and plug the two shaft holes. I'm hoping someone has one of these springs in their stash of parts that is in near mint condition that doesn't need it and is willing to part with it or if anyone knows of a source for a new replacement spring, let me know.
Thanks!