Types of Brake Lines

Hello fellow truckers, I'm repairing my brake lines from my master cylinder to my proportioning valve.  I bought some stainless steel lines for the job, the only problem is that when it came time to flare them, they would not stay in position in the flaring block.  My concern is that the steel is too strong and will not flare so easily, is there any substitutions for brake lines. Perhaps a more flexible steel or aluminum?   any comments or suggestions are welcome. This is my first (car) '69 c-10 so id like to do a good job on all my repairs.  Thanks guys  

Generally, you need a flaring tool that is specifically designed for stainless steel.  Due to its nature, Stainless can work harden and become harder to work with. Several companies, such as Inline Tube or Classic Tube, can make pre-bent, already flared brake lines in Stainless or O.E.M. steel.  Both of these companies advertise in Classic Trucks.  They can make factory replacement lines, or if you have a custom set-up, they can help with that, too. Ironically, a friend of mine just ordered those same lines for his '66 C10 in Stainless from Inline Tube.  I don't remember the price at the moment, but the fit and finish was very good.  If you have the factory style set-up with the prop valve attatched to the master cylinder with an "L" bracket, I have a spare set of regular steel lines that I would be willing to give just so they get some use, and get them off my spare parts shelf.  Let me know if you are interested and we can set something up.  

Thank for the help Vintage.  

No problem.