My wife has the 97 Vmax 600, 144 studs, heat excanger protectors front & rear. I'm told some 97 600's had piston problems after 3000+ miles, so I may replace hers next year. I will look into the spring for you and post it. Have him read his setup manual for the rear skid, lots of adjustments. When it's set up right, I think it's the best ride around.