Having built the y-pipe from scatch, I don't see how you could do it with flex pipe. Bite the bullit and spend the $300 at Banks and be done withit. I know it's a lot of money but after you see the bends in the y-pipe you will understand. Also remember all of the design work that went into that y-pipe to get the correct flow into the turbo from both manifolds without restricting flow. We spent 8 hours custom building mine, so what your time is worth.