Sorry it took me so long to get back regarding this problem. Originaly I said that the linkages looked fine on the carb. They are operating as they should be, however after pulling off the carb and looking at it closely, I realized that the throttle linkage was not returning all the way. As I mentioned in my previous post, I converted the carb to manual choke about a year ago. When I did that I just diconnected the linkage for it and left it on the carb. Well, it took a year, but a piece of the choke linkage spun around and lodged itself in the perfect position at the base of the throttle screw. I could not see the problem until I pulled it off of the truck. I pulled off the old unneeded linkage and it runs perfectly now.

Thanks for all of the replies that were listed. I appreciate it.