15's are aftermarket only and not easy to find. I have had several sets made mostly 8 or 10 inch wide. I do have a set of Centerline and aluminum slot frontrunners 4" wide laying around. Let me know if you need to use them as they are not for sale.

The funny thing about science is that if you change one miniscule parameter you change the entire outcome to the way you want it.

JB Rhinehart, Realist

A-Body's RULE!