Why not rivets?
For frames where rivets were originally used I prefer to use new rivets, installed hot.
If you don't use rivets, do use the proper frame bolts and nuts. They can be bought at a good heavy truck parts store.
The down side to using bolts in old rivet holes is you often need to re-drill them to the next bolt size up to achieve a snug fit between the bolt and the hole.
A loose fitting bolt in a frame or suspension bracket is asking for trouble. Because a frame does, and needs to, flex it can cause sloppy fitting bolts to weaken and break.
Grigg
