Verified answer

Look for a 1973-1987 C10 at a salvage yard and rob everything under the subframe. It will all bolt up easily.

Also make sure to snag the brake lines, porportioning block, master cylinder/booster and the rear axle if you have a 6-lug '63 so everything matches nicely.

Disc brake conversions can be gotten fairly cheap for just the anchors. The calipers will probably be your biggest expense. I wouldn't the surprised if the spindle and hub from a new chev fit. You don't like that front wheel lock up or what?

A newer Chevy truck with disc brakes should work.

Find out when they switched to discs & get the parts off one in a junkyard.

Unless you are road racing, you don't need the latestcoolest most expensive stuff (like Wilwood, etc)