Hey, Big Inch. Just put as much crome moly tubing in there as you can. Then get a gallon of Goriila glue to hold it together. Then you're good to go! Some more sound advice from your uncle.
Not to go against the grain of what you're saying but professionals like Bill Lutz are using RTV now-a-days.
I see what you did there. LOL
You guys joke but I know of one of our local No E.T./Grudge cars that the track officials finally told our buddy with a sleeper 10.5" tire Mustang with no cage & factory lap bet, we know how fast you are going & we would appreciate it if you put a cage in the car. He did, it is all glued together plastic PVC with some roll bar padding on the door bar & head bars to look the part. The officials never said anything again. It is funny watching him climb over the door bar & it flexes as he gets in & out.
Not for me though. I would rather be safe.