I think this points out why most all out performance oriented vehicles these days are of the coupe and not roadster variety for the added ridgidty of the structure, unless they are fully framed or a purpose built monocoque structure for high HP/Torque powerplants.
I had a couple '67 rags with 396 engines (one stock 325Hp and the other non-original BB car with a 396 built up to unknown output. The last one was a real P.O.S.! It bent and flexed in all the wrong places and friends swear they could see the pavement thru the lower door seam when I was on it in a corner. I swaped it back to a SBC and sold it before it twisted in half, but it is still on the street in So.Cal. in SBC form so maybe I didn't hurt it to bad.
Now I use F-body coupes only for performance bases.
My street cruiser is a '68 rag with a mild SBC.