Small block brackets, pullys, pan

Are you using the cast iron water pump or aluminum one? All the brackets and pulleys are different for each setup, and as mentioned A/C and non A/C are all different too. No mixing and matching unless you like to modify things. Radiator connections are another thing to consider when it comes to using stock parts. Keep in mind that the '72 and later balancers and pulley used an evenly spaced bolt pattern and the earlier ones had one offset bolt. You can modify either setup by slotting one hole, but, just nice the get the correct ones without having to do it. Timing marks are another difference in the '70 and newer, and '69 and older setup. Since you have the later timing cover (and I presume balancer) you may a little trouble seeing the timing mark if you use the cast iron water pump with that combo. Maybe add the earlier timing indicator and adding another timing mark on the balancer might be a good idea.