I have converted my 1970 SS Chevelle over to disc brakes in the rear of the car. I have ordered and received a new power disc brake booster, mastercylinder, and combination valve designed to work with a Disc/disc system.
My problem is that the new combination valve is longer than the original valve and my new stainless lines are going to require shortening and re-flaring.
Can anyone recommend what type of flaring tool will work well for this kind of work on stainless brake tubing? And exactly what type of flare do I need to reinstall on these brake lines for them to seat in the new combination valve?
My stainless lines came from Ground-Up and they look like a standard double flare automotive, but I'm not sure and don't want to screw these lines up without more information. I have a standard flare kit for carbon steel lines, but I dont think that will do the job on stainless. Thanks for any suggestions.

Most aftermarket stainless brake lines are already annealed so re-flaring should not be a problem if you use a quality double flare tool.

Bill, thanks for the reply back on the flare issue. So, if I understand this correctly, I can cut to length where I need it and use my flare kit that I use on the carbon steel brake lines with a double flare. Does the annealing process allow the brake line enough "elasticity" to flare without splitting? Would you use any lubricant when flaring it because its stainless? Thanks again.

1) I can cut to length where I need it and use my flare kit that I use on the carbon steel brake lines with a double flare.
2)Does the annealing process allow the brake line enough "elasticity" to flare without splitting?

1)Yes, I've done it many times.
2)Yes, that is how they're able to be manufactured originally.
And, no lube needed.