Which wilwoods

[akrapovic]

New guy with another new guy question. I'm trying to pick out my wilwood rear brake kit. I have a 9 inch with what I believe are the big ford new style housing ends(see picture.)

I'm trying to figure out whether I need the 2.36 or 2.50 offset. Not sure if this is specific to what style housing end I have or if I'm going to have to measure. Here is the wilwood kit I'm looking at:

http://www.jegs.com/i/Wilwood/950/14...0002/-1?CT=999

Thanks in advance.