Fordcoupe, I am in the process of re-plumbing all of the hard brake lines on my truck. I converted it from a swing pedal brake firewall mounted booster and cylinder to a thru the floor master and clutch master cylinder. When I ordered my master cylinder and clutch master cylinder mount it came with residual valves for both the front and the rear brakes. A 2lb valve for the rear and a 10lb residual valve for the front, both of these valves are in fact "Inverted Flare" so they do make them.

If you need any pic's are the name of the supplier let me know. I am sure that you will find residual valves that take flared fittings as I have two of them.

Roland