Proportioning valve metal line

[truckin 79]

So I need to change the metal line going to drivers caliper. I buggered up the flare nut, what a suprise that never happens to me. Some word of advice for anyone else doing this, remove stamped 15/16 nut first, it is much easier to get to flare nut and get some leverage pushing it towards caliper. I used a crows foot to try and get line off in-between frame rails and rounded it off. Anyway I bought some metal brake line to bend up my own line. I am wondering if it is easier to just try and do where proportioning valve is or pull prop valve out slightly. I am just going to cut old line as close to flare nut on prop valve and use a ratchet. How hard is it to pull prop valve out slightly? What was GM thinking putting proportioning valve underneath the bottom of radiator?