you have to measure the width of your strings from 1st-6th on your bridge and the width at the nut. i think if you nut string width is 11/16 or more you want f- spaced, the bridge is like 14/16 or more.....dimarzio's web site will answer you question for sure, look for the "frequently asked questions" bit in their tool bar. i bet you need f-spaced though.