Bench to Buckets...need help!!!

I believe the floor is shaped that way on the drivers side for catalytic convertor clearence.If you look at the reproduction four speed hump they are designed off of a later model a-body (to fit the buldge) and have a gap when you use them in an mid 70s or earler car.You have to hammer them down to make them work-dont ask me why the aftermarket cant get things figurerd out!.