I am looking for a topper or tonneau for my '81 F100 stepside. They seem to be difficult to find for my model. It seems that most toppers use inside clamps which is impossible on my year of stepside. If anyone knows about where I could locate one of these, I would be grateful for the info. Do these types use the bed corner holes to secure, some type of clamp, or will I need to drill holes?

 

They both use the inside clamps but I'm sure you could find some other way to mount them.