Ruger Super GP100 x 9mm, rear sight question

[mikeAZ]

Thanks to all,  I've gotten a lot of help answering my many questions.( Ruger Super GP100 x 9mm ) ...BUT I'll need a rear fiber optic sight. The info "net" says the rear adjustable sights are the same on most Ruger revolvers.  Has anyone tried to use a rear fiber sight or insert on the Super GP 100? One reply said the rear coil elevation spring was to short and he had to use a slightly longer one for more elevation. (was not super GP 100 post) Thanks for your help.