I'm thinking of installing a Drum-to-Disk conversion kit onto our 68 GTO front end and had some questions. First, we have 14" wheels and would like to keep it stock, but I've only found one kit (OPGI) that suppose to work with 14" wheels. Has anyone ran into this issue, or have used the OPGI kit. Or, is it just better to go with 15" if you intend to install disc brakes on the front? Also, how difficult is the installation of these kits? Thanks.