I'm currently putting the complete chassis stiffening pack and frame ties from US tool in my B Body. Not sure where you are in WI but I'm in MN and you're welcome to come check it out. My last car had 500HP and I did weld in frame ties that only fastened at the front and back (not along the floor). I never took it to the track but like stomping the throttle on my way to the Saturday night car shows. When I sold the car it was pointed out that the car had started to twist. I'm not a structural engineer but the material from US Tool is thicker than the floors, frame, and rockers on the car. It's just shy of $800 to put all their stiffening products in the car and really doesn't take too much more time than just doing frame ties. Theirs doesn't require cutting slots in the floor so the carpet will lay down right and the stock appearance isn't changed at all. I can't tell you how well it all works yet, but it seems like reasonable insurance.