Gary, my F3 has 1/4" brake lines and the 72 F250 Dana 60 has 3/16 lines to the wheel cylinders. I kept it that way by modifying my Tee fitting and using two adapters. Been working trouble free for many years and yes it stops well.
Here's the stock hose and block. The long nipple is from the 1972 F250. That hose was cut off by the PO and wouldn't have worked anyway. I had to drill out the block so the nipple would fit. It originally had a hose going up under the bed for a vent. The small breather is the original from the Timken rear.
https://cimg8.ibsrv.net/gimg/www.for...bd343ba6b5.jpg