We’ve converted to a dual master cylinder setup on several ‘65 and ‘66 Chryslers by using a block from Inline Tube and running new front lines. Just ordered a couple more of the blocks at Carlisle. Seems like two of them were around $65 total.
No changes at the wheels at all aside from bleeding the brakes. Works well and gives me more confidence it’ll stop. Had a brake issue on my ‘65 convertible years ago and lightly tapped a tree in the yard upon realizing I had no brakes. Thankfully no major damage, but never again. I like originality but I consider this a safety upgrade for me as well as others on the road.