The importance of using the correct fasteners in all areas of the machine can never be overstated - this 5x8 Hex head Bolt is no exception, and is specific to this application in the assembly.
Threads will be accurate, bolts will be hardened and tempered correctly with the correct plated finish. In short it would be unwise, to say the least, to use anything other than genuine factory supplied fasteners!
Please make sure part numbers ordered are compatible with your model. Use genuine OE fasteners. Why take the chance with any other make?