I have a set of 3 piece 19" wheels that will fit the chevelle. You can view them by checking out my post on Lat-G:
https://lateral-g.net/forums/showthread.php4?t=52755
If interested, I can send more details and pics. They are brand new 3 piece Niche Stuttgart wheels with brand new Michelin tires. 19x8f & 19x9.5 rear custom made to fit 67-69 camaros but will fit your chevelle as well.