I had a 64 Ford Galaxie (same basic front suspension as your 57) that I put a power rack & pinion conversion kit on. Made a huge difference in how the car drove and allows you to keep most of the original suspension. I got the kit from http://www.wurthitdesigns.com/ It was a good kit but the guy was slow and a little flakey about getting the kit to me. He has some nice 57's on it site, too. Check it out.