Katana 1989 600 4-1 Pipes

[vonrapier]

I have a Katana 1989 600 and I have taken off the 4-1 pipes to have them sandblasted and painted. But upon trying to reassemble them I am noticing that there are spots to attach 2 springs on each pipe from the header to the head.


The question I have is does anyone know what kind of springs do I look for? So I can reattach the pipes correctly. How long etc?