Are you planning on doing this so you can use the 12.88" brakes you have available? I ask because I converted my '46 Ford pickup over to Speedway brakes (11" rotors, Chevelle calipers) For $315. Complete. You may end up spending more than that for the custom axle / spindles and related machining. And my truck stops just fine - way better than the original hydraulic drum brakes. So - maybe sell your Wilwood parts and consider a complete kit from Speedway or wherever.
