Second to hot rivets is grade 5 or grade 8 bolts. The bolts need to fit really tight. I replaced my front spring mount rivets with grade 5, 1/2”-20 shoulder bolts, making sure the shoulder went all the way thru so none of the threads contacted the bolt holes.
Here is the thread where I replaced the rivets. There was some really good advice from fellow ‘Bolters on how to accomplish this. As you will read, it’s more than just putting in replacement bolts.
