I say leave the rails on, I have two 70s one with and one without the rails. I bought the one without rails, and not too crazy about it. The person who cut them off did a piss poor job and never welded them, took a few hours just to clean the filler out weld, looks ok but I like the rails on.
I did mine for one reason only really. Mine had a decent amount of rust in the channel. If it weren't for that I would have left them in place too. But for me the easiest way to take care of the rust was to just cut it out and move on.... Glenn
You must do it in short sections, If you cut them all off the top will peal like a can. essentially its like a can (food can duh) and as soon as you start cutting it will begin to pull itself away from each other. Saw something on Overhaul as well stating similar.
How many gauges? I mounted a 2-gauge chrome bracket (electric oil pressure & water temp) underneath the front package tray, in the center, ahead of the floor shifter. If you feel underneath the plastic package tray, you will notice a gap between the front edge, and the tray part I used two plastic license plate type fasteners - epoxied with J-B Weld. These are the type that expand, when you run the screw through them. Measure & mark a centerline (or wherever you desire to mount it). Put a thin coat of silicone grease/oil on the screws, lightly screw into the plastic pieces and to your bracket. Mix the epoxy & apply to both the outside of the plastic fasteners and the screw locations on the package tray. While pushing on the screw/bracket, tighten the screws. The plastic pieces will expand in the gap. I don't remember if I had to file or trim any part of the two plastic mounting pieces.
