they say due a complete swap, But Im thinking like daliant that the brakes will be mushy. I'm not thinking I should do a complete swap, but what about the lines coming off the master cyclinder to the diverter valve?
Yes, you can do braided line from the master to your combination valve. There is a difference between the braided line used for fuel systems and that that is used for brake systems. Lines for brake systems are made of TFE. It is a braided line with a Teflon core. It will withstand much higher heat and pressure without distortion. Which makes it an upgrade from standard rubber reinforced flexible brake hoses that came standard on our cars.
Technically speaking, you could use it for your entire brake system, but why? Laziness would be my only answer. It's not cost effective, it would cost more per foot than stainless hardline. It can't be weight savings, because it weighs more per foot than stainless hardline. Not to mention you would probably have to use three times as many clamps to keep it in place. So, I'm guessing your "Speed Shop" can't figure out how, or it's too complicated, or takes to much time to properly bend or flare a hardline.
