A 7 years back I ran a set of the "new" Crowers in Joe Fontanas 12 Port GMC and they had tie bars. Bill Harris helped me get a set last year and they too have tie bars. Some of the rivets needed to be ground to miss the push rods.
My old set needed a bar mounted to the lifter gallery to keep them from turning and I liked that best. You need to spin the pushrod to break the oil suction on a tie bar or you can pull the lifter out and loose the tie bar...been there done that...not good.
I've never seen a "stock" cam be ground for a roller...They were all made from blanks with much fuller lobes...Good Luck
