Many years ago I replaced the steel guides on my made in USA 14" Delta and of course it was a vast improvement. About 6 years ago I ran into a deal on an 18" Chinese Delta with OEM bearing guides and in the process of tuning that machine I found that the dollar bill trick between the blade and the guide does not work with that sloppy adjustment set up. The carter guides can be dialed in using a shim such as a dollar bill then tightened down and you are ready to go. The OEM guides require guessing the position, tighten, check then try another guess until you get it right.