valve differences between '85 and '86 VF500F

anyone know specific details about the differences in the valves between '85 and '86.
They have different part numbers. Also , VTR250 seems to have same exhaust and intake as '86 VF500.
Middle code seems to be the key KE8 for '85, KM3 or KV0 for '86.

I'm looking to get some valves and want to know all the details

 

They are significantly different. I think the 86 valves are shorter. They are very hard to come by as are the valve springs. You might be better off trying for a spare engine and cannibalising it. (There are posts on this forum that cover this but I find the search function pretty poor.)