It’s really just wrench clearance for bleading and installing brake line too that is difficult, possible I believe but difficult.
It’ll also look a little better with the shallower drums.

I don’t know of any aftermarket flanges. You could harvest used ones or make new. Welding them on square to the axle will take a little care.

•1951 GMC 250 in the Project Journals
•1948 Chevrolet 6400 - Detroit Diesel 4-53T - Roadranger 10 speed overdrive - 4 wheel disc brakes
•1952 Chevrolet 3800 pickup
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"First, get a clear notion of what you desire to accomplish, and then in all probability you will succeed in doing it..." -Henry Maudslay-