I have this valve adjustment order that I learned way back when I worked at a Chevy dealership 13 years ago. I broke the process down and realised it will work for any engine. You will always have two cylinders at TDC at the same time. On a SBC and Datsun L6 (and many other engines) #1 and #6 are at TDC at the same time, one will be on the compression stroke and one will be on the exhaust stroke. So get the engine to TDC compression stroke on #1 and adjust both of those. Then follow the firing order adjusting exhaust valves. Skip #6. After #6 follow the rest of the firing order but adjust intake valves. Then just rotate the engine one revolution and adjust the rest.
Datsun L6 TDC #1 compession intake valves 1-2-4 exhaust valves 1-3-5
#6 compression intake valves 3-5-6 exhaust valves 2-4-6
Gen 1 SBC #1) intake 1-2-5-7 exhaust 1-3-4-8
#6) intake 3-4-6-8 exhaust 2-5-6-7