I am replacing my subframe with another one with disk brakes. The brakes shouldn't matter, but the mounting hole sizes are different. My old frame has no rust (I crashed - damn drum brakes!), and the holes measured 1 1/2". My 'new' frame has 1 3/4" holes. There is quite a bit of slop with the new frame mounts in these bigger holes. Is this normal? Can I just bolt up the new frame and the rubber will expand to fit the bigger holes? Do I have a different frame? It looks exactly the same other than this. Please help, I'm stuck right from the begining!