If you use a floor jack under your Cobra frequently you probably know the trick of lowering the nose last and moving the jack to the side of the
oil cooler scoop to clear it. This even needs to be done with a low profile floor jack. I have done this hundreds of times and it worked well for me until.................... the jack pad slipped out from under the tubular crossmember. Of course it only happened because I was twisting the jack with it still too high. It slipped off the tube and crunched into the front of the road race pan and beat it up pretty well. It also scratched the frame paint pretty well. After trying to get my attachments down out of my stomach and back to their usual residence I contacted the customer who was very agreeable and we changed his pan out to an original Aviaid road race pan so it looked like everyone was going to be happy. That is after I figured out you can change an
oil pan in the car with a CSX frame. Even with it being a stroker motor it was possible with the crank in the right position for the pan to clear the 3" tubular trans crossmember. It did take some spacing under the trans mount with it up as high as possible against the tunnel. Having resolved that I wondered how I would avoid doing that again. Spending most of my time under tube frame cars and having seen the original Shelley jacks it was a simple solution. Jack pads made from sections of 4" pipe with an EPDM lining and either a stub or socket to fit your jack. Fast and easy to change over and very secure under tube frames. Especially when swivelling them. I have made them for mine and a couple of customers jacks also in different attachment styles as you can see. I have a stash of the curved plates if you want to make one for your jack or let me know what your jack measures and I can make them for you.
Don't get off the jack like me and be safe working under your cars.