I had the same problem on a slant. When I found a 3/4-16 bolt long enough, the threads were only about 1-1/2" (not enough) and the rest was smooth shank. I went to a really good fastener store and bought a piece of all-thread instead. The good news, it worked like a champ. The bad news, I had to buy a 36" piece to get any at all. I cut it into about 5-6 pieces, keeping one for myself and giving the rest away. I double nutted the back end to hold it still and ran down the balancer with another nut and washer.