It's probably not a bad isea to make them aware of the 24X reference ring. Also, if you're going to have a mech. do the job for you, cough up the extra dough to replace the front seal - it's cheap insurance. Other than that, they shouldn't need any instructions, although the pulley does come with some directions, and a full install is detailled on
www.fastfwdperformance.com. You must supply a new belt; I think I used one 85.5" long.