These engines, especially when heavily modified have tremendous torsional vibration. In most cases the flywheel bolts do not come loose and cause the flywheel to come off. Usually the flywheel shifts back and forth under the fully tightened bolts because of the torsional vibrations, and this causes the bolts to work loose. Locktite and safety wire will not help to prevent this. Only using a higher torque value (stronger bolts if needed) or additional dowels in the flywheel/crank will prevent the flywheel from shifting and working itself loose. According to my source 98ftlbs is the torque specification for the stock bolts. I would use at least 115ftlbs with the engine you are putting together. Consult an engine builder for their recommendation.