Fast visit to a Pick a Part ought to score you those lines, just bring the correct flare nut wrenches or crow foot wrenches to keep from mangling the invert flare nuts on the case and tank fittings. When I did my 700 swap into the van, seem to recall that I used the 350 lines, just had to tweak them at the bends to get a better alignment headed towards the case fittings. They have to line up or you will either not get them to thread in; and they ought to thread in by hand if all is well, or you will cross-thread them and murder the threads meaning you will have to find replacements.
If you want to go fancy, you can get A-N to invert flare adapters to screw into the T-case ports and the radiator inlets, then all you need is two hoses made with AN Flares or that Ni-Copp made with A-N ferrules and nuts and you arfe good to go. The AN needs a different angle of flaring tool but you only would need one flare, not a double flare like a normal brake line; easier and simpler to do and less chance of splitting the tube or coming up with an eccentric flare surface that won't seal. Also the Ni-copp is just a little softer than normal steel line meaning it is easier to shape to fit tighter positions without the risk of kink occurring. The brake lines on my 85 S/S are Ni-copp and so are the ones on my S-10. Got them so close to the bends like the originals had that they lined up to the ABS block and the frame brackets without too much further persuasion at all.
Nick