A guy at work is selling the Wilwood BBK from his 2013 C6 Corvette Grand Sport. Wildwood Aerolite 6R Calipers, Bracket, Brake Pad kit with Front Promatrix 14 inch diameter vented two piece rotors and Wilwood SS brake lines. Has anyone fit this large of a rotor on the E-body? I've got a 73 Cuda with OE disks on the front. I went on the Wilwood site and only kits I could find using this 6R caliper require Magnum Force 2" drop spindles but only with their 12.88" rotors. Was hoping that someone has paved the way using standard spindles. I don't know why they don't list the bigger rotor but will call and try to find out. Seems like it should just require a different mounting bracket as long as the offset in the rotor is compatible? Was hoping I could pick up his kit "cheap" and then either Wilwood or Dr Diff hubs and then address the mounting bracket. Am I missing anything? Are these calipers essentially the same as Brembos from a mounting perspective?

You need some more pictures to know what you have. If those calipers are radial mounts then you should be able to build a bracket kit that works. The Doctor Diff hubs are a good choice or buy a set of hubs from Baer. You will need to know what you're doing to get everything in the correct place so if you don't have experience building big brake kits you might want to consult with an experienced street rod fab guy. You'll need at least an 18 inch rim and maybe a 19 inch rim. Just depends on the shape of the calipers and the rim. The bolt pattern on those rotors will be wrong so you will need to redrill them to fit the hubs.

Looking at the Wilwood site it appears that they are radial mount. With the 14" rotors they show 8.13" from center to the outside of the caliper. Was hoping to stay with 18" wheel so I need to look into that closer. Site says they "may" fit 18". I could live with smaller diameter rotors but doing that may make the deal untenable if I have to replace the discs.
https://www.wilwood.com/BrakeKits/BrakeKitsProdFront?itemno=140-12629-R