By 62the 34 inch frame was pretty standard. Crossmember spacing might be different, but these frames were not heat treated so they drill easily. Instead of rivets, flange bolts can be used. Flange bolts were used by large trucks until the mid 1990's when Huck bolts became the standard. This is a source of flange bolts. http://www.imperialinc.com/items.asp?item=0191490