Model A head gaskets tend to ooze a little, might not be a problem. Once you start it, and get it warmed up, you might gently see if you can re-torque it. I have never met a Model A that did not need re-torquing. For most of us, we torque all but the front 2 nuts to 55 pounds. The front 2 which attach the water neck or water outlet most of us only torque to 50 lbs. The ears on that water neck are prone to breaking off they are so thinly cast. Go easy. There is a pattern in Brattons catalogue. Get catalogues from the major suppliers, they are a wealth of info even if you do not buy anything.
The original fans are very very prone to cracking and having a blade sent into orbit. This disturbing feature has resulted in hoods and radiators being sliced open, hands and arms being cut off, and death. Change it if original. A modern aluminum 2 blade fan will be all one piece, with no visible gap between the blades and the pulley. There are pix on this forum.
Off the top of my head the systems which are not in synch with the modern day world of the chevy 350 are:
1.Ignition wiring (very diff than what you are accustomed to)
2.That darned fan blade. If orig., Do NOT trust it or weld it. Throw it away
3. Method of timing
4. Use of generator 3rd brush
5. learning the tricks of the Zenith carb. Of course, all carbs, even rochesters, have their quirks
6. mechanical brakes
All this stuff is covered here on the barn and in Les Andrews books. You wouldn't work on a 2014 Silverado without a factory manual, why would a Model A be any different.
Good luck and post as often as needed.