The only issue I had with ATI dampers and ARP crank bolt/washer was on a old pushrod R302 block based motor I built. The damper had a huge radius out from the center bolt hole. I had the chamfer the crank bolt's washer on the outside edge so it made direct, flat contact with the face of the damper. I assume the damper was a very tight press fit, I've never messed with 4v engines to this point. Sure looks like the bolt snapped first and then the damper and crank snout twisted. The bolt end in the crank did not twist.