I just bought a used set of itr valve springs and retainers for my GSR. They all look exactly the same. I can see paint on them but its not clear enough for me to be able to differentiate between them.

I searched around and noticed in some years they have the same part number for both. All of them look to be the same height and have traces of blue or green paint on them.

At this point i am thinking they are the same. The gsr intake valve springs i pulled out of my gsr deff. have a thinner coil and are taller. Should I just take these to a machine shop to test the spring rate? They are in better shape and are stiffer then the GSR Intake valve springs I pulled out of mine.

Heres the link I found on part numbers.
http://www.lightningmotorsports.com/techhonacua.htm

 

From what I understand, one of the sets either int or ex is a slightly taller than the other for the oem itr springs. I have also read and seen people run any combination of those 3 dual valve springs (itr intake itr exhaust, and gsr intake) and work just fine for itr cams. My buddy is currently running itr exhaust and gsr intake springs.

 

Retainers are the same, itr has it's own intake springs(yellow) and for exhaust side it uses gsr intake springs(blue).