What would a 20" steel wheel weigh...55#, 60#, more? You may be almost doubling your unsprung weight on the car by going to the 20" steel wheel.

I seem to recall seeing a few show cars over the last ten years that had custom aluminum wheels made to look like steel. Its possible, but not cheap. I think Ray Evernham had some made and I want to say there was one other vintage stock car looking vehicle out there that had some made up to look like steel.