I've never seen anything like that offered as an oem wheel, not to say it never was, but maybe a dealer upfit option? American Racing and Vision both make wheels like that in 6 spoke 6 lug, but the hexagonal shape around the lug bores is different along with the center cap style (aside from just having the Chevy logo). A pretty common style to be named Torq, Torque, Thrust, Torque Thrust... ect, searching any combination of those and 6x5.5 or 6x139.7 might put you in the right direction.