When running gas lines be mindful of heat (obvious) I would try to stick with running them on the frame rails when I boxed my willys frame I ran them on the inside of the rail so as not to heat them up on the headers and muffler. Since they are sitting next to the trans I would guess you may have no problems above it either but heat does rise. I wouldn't attach them to the trans though, run 'em on the body. boy I love how I contridict myself