The exhaust spring pair I removed yesterday has inner length 1.4" with outer 1.55". RGM supply 1.5" and 1.65" respectively. So both have lost 0.1".
I've already ordered and paid for new ones, but now I'm in two minds as usual about fitting them. I doubt if I'll be taking it to 6000rpm, and higher spring pressure will just add to valve gear loads. What would you do on a grey December day?