Years ago I bought a set of 4 non adjustable square tube rear control arms for my ragtop. Then found these aren't exactly the hot setup, what with the binding of the poly bushings. Picked up a set of Edelbrock adjustable uppers at a swap meet. Was thinking if I could convert the front bushing on the lowers to a spherical type bearing like used in the Edelbrocks, I'd be all set. Anybody ever do this? Have a small machine shop set up in my shop, so machine work isn't a problem. Any sources for these type of bearings? Also I've lowered the front of the car and am getting ready to lower the rear once I get my wheel situation straightened out. Any advantage to lowering the lower control arm mount on the rear axle? Is this more of a drag race thing, or does it help general handling too? Thank you in advance, Jim.