What’s the best kit to put disc brakes on a 63 Dart

The Wilwood kit will not work with the original SBP wheels. The hub diameter on the Wilwoods requires a 3.050” hub bore.

In fact, the Wilwood kit with the new hub they started using a few years ago fits very few SBP wheels still available.

Really defeats the purpose of staying SBP if you have to buy all new wheels anyway.