I am putting my 69 back together and would like to know what is the best thing to use to finish my gas and brake lines with.

I've always had great success with clear urethane, or clear VHT high heat in a spray bomb. In the case of the urethane, once it dries, you'd want to hit it with OOO steel wool to knock down the gloss for a more natural appearance.

If your using new steel lines we just clan them good with a rag and some paint prep and then shoot some martin senor cut in clear on them from a spray can. Its comes out in a matte finish and you cant tell it has clear on it.

If youre cleaning and re-using the original lines, just a clear wont work on the bare metal. Rust will form underneath. You will need to use a metal etch product to prep it for the clear.

If using new lines (which I recommend), they usually dont need much. I usually just give em a wipe down with boeshield.