I know when I do mustangs we put a cross bar in, 2" x 3" rectangle tubing from frame rail to frame rail with a hump in it for driveshaft clearance then have your downward angle bars attach to that. Floor has to much flex.
Thanks Dave. My good friend, Jim Kline, at GoFast Productions can take credit for the cages in both cars. No Sir. Skylark has stock inners. 275/60-15 drag radials. I have the front loop, on the Buick, welded to the trans crossmember. The rear loop is welded to the frame.
No kidding. Its interesting looking at a 4 yr old thread and thinking man did I say that. I will have to really dig deep to top some of that stuff.