I forgot about that. I found this blurb from “Vulture”
“Richard Pryor was one of five writers who worked on Mel Brooks’s 1974 western comedy Blazing Saddles, and he was Brooks’s original choice for the lead role. On the movie’s DVD commentary, Brooks recalls going “on bended knee to every studio executive” to try to convince them to hire Pryor, but rumors about Pryor’s mental health and drug use, as well as his vulgar stand-up act, caused the studio to reject the idea. Cleavon Little did a great job in the role and certainly plays it differently than Pryor would have, often serving as the straight man where Pryor is more prone to being the funny one. Still, it would have been fun to see what this classic would have been like with Richard Pryor in the lead role. Pryor had tackled racial politics at length in his stand-up act and this was a great opportunity for him to address similar subject matter on the big screen. Pryor and Gene Wilder always had great chemistry together, too, and the two of them starring in a film that’s more acclaimed and successful than anything they actually made as a team is a missed opportunity for both actors”
