I've seen a few rear ends with slight V shaped tubes welded right on the bottom of the circle (if you will) then outward to the coil over mounts to prevent twisting, like this.
sometimes off road vehicles have a truss under or over the axle housing, for vertical loads. The one across the back is for front/back loads, caused by the tires pulling the ends of the axle forward, while the inertia of the car, acting through the rear suspension, tries to hold the housing back.
SD I don't recall, may be in the 200 lb range, they are QA1's, they have a pretty informative fact sheet (pdf) on their website. https://www.google.com/search?q=qa1...CgAQHIAQi4AQLAAQE&sclient=mobile-gws-wiz-serp
From a been there done that. Just take the tank off and clean it out and be done with it before you run it. You are going to take it off sooner or later. Later being after you plug up three or four fuel filters if you have them in front of the pump. It might be a pain in the **** to clean the tank first but it is a royal pain in the *** to lay under the car changing a plugged up fuel filter.
Yes, but not in a rod. I used a f100 9 inch housing for a Jeep CJ project. Much easier to bend a housing doing off road than street applications. Had a friend that is a professional fab guy do the welding. He worked on it all day off and on so it did not warp from heat.
The 9" in my 58 t bird broke at the right side axle tube. Had the coil spring rear end. I welded it up and put a strap iron brace on the bottom.
If the brace Squirrel has works, I would go with it. With his hp, and the fact that he drives his car to a race, steps into it hard, then drives to another race, it would be something to consider. I would rather doubt he would be tooting it otherwise.