Hi FTE,
I currently have a 73 F250 4x4 that had a bad break (beyond repair) on one of the front hubs of the stock, closed knuckle D44. To make a long story short, I have a D44 from a 77 F250 that I have installed in my truck (a disc brake and power steering upgrade ). I am in the process of plumbing brake lines (doing a hydroboost system) and had trouble hooking up my new rubber brake hose (bought from rock auto for the 77' axle) to the stock 73' hard line to connect the caliper. The female fitting of the rubber hose that connects to the steel line is 7/16, however my hard line (that was used for the drum brakes) is only a 3/16 line with a 3/8 fitting. It looks like the line for the back brakes is a 1/4 line.

I suspect that I need to: get 1/4 line with a 7/16 fitting and adapt it to the new prop valve I am getting OR get a fitting that steps up the stock 3/8 fitting to a 7/16 fitting (I fear that this will reduce brake pressure though).

Bottom line is that I think the stock 73 brake lines that were intended for drum brakes will not work for the dual piston calipers on the front.

Anyone know what would be best to do? I want to be able to stop the freight train of a truck safely. Some help would be greatly appreciated.

Cheers.