I just put one of Wilwood's new classic discs on the front of my 68 GT350. This kit fit inside the ten spoke wheels. Without hesitation I would recommend this kit. The retail cost for the full kit was about $700. I can't believe how well these brakes work. I left the drums on the rear for the time being but the Wilwood rear kit is about the same cost as the front kit. I did learn that you can assume ALL these kits including the Wilwood are designed to fit drum spindles. We had to drill and tap my disc brake spindles to install the caliper bracket. The shop that did my work was doing a SBC front conversion on a 66 2+2 drum car. Said the SBC kit had a lot of issues like things lining up properly.
Another thing I learned is that most of those kits like the SBC are copied from the original Kelsey Hayes discs that were stock when our cars were new. And like I said they are made to fit drum brake spindles.
Once my car's spindles were tapped my Wilwoods went together like you'd expect. These are GREAT brakes. I also replaced the power booster and master cylinder. Brakes are one place I would not go cheap. By the way, one of my big concerns was whether this kit or any kit would fit my 15" ten spoke rims. NO one would promise that. I talked to all the vendors I could find. And all of them said if the discs were installed on the car they would not take them back. This Wilwood kit fits a 14" wheel. I got them from CJ Pony cheaper than what Wilwood was asking for the same kit. And CJ said as long as I didn't put them on the car, CJ would take them back. CJ had them in stock and to me in a couple of days. My Porterfield rear shoes took an extra week to get to me. I am happy to say I have really great brakes on my car now. The whole project including labor, the booster & Master cylinder and Porterfield shoes ran me about $2,000. Worth every penny.