Valve springs

Anyone know whether valve springs for 500/650 Triumphs are the same as those for T140s? There's a set on Ebay I'll buy if they will work on a T140 head, without modifying anything. Hopefully, I can post a photo...

Maybe there is a crossreference, Can you compare the free length amount of coils, and wire diameter, etc. If some specs line up, check spring pressure at installed height.