Are your tires radial or bias? Bias tend to flat spot more easily, even over night but once they get driven for a few miles and warm up generally run smooth. I prefer machined aluminum wheels because they typically run truer then stamped steel wheels. I would suggest maybe breaking down the tires from the rims and see if in fact the rims do run true or you have one that is fubar. I had a set of aluminum wheels about 30 years ago had the bolt holes drilled way off and had a lot of run out to the point ofnot being useable.