I always do the companion cylinder way, throw a degree wheel on the crank and put it on top dead center.
For our 235s, I will start by putting it on number 1 top dead center with the valves rocking on 6, adjust number one intake and exhaust, rotate the crank 120 degrees and do the valves on 5, rotate the crank another 120 degrees and do the valves on three, then another 120 degrees and so on through the firing order. 1.5.3.6.2.4

1953 Chevrolet 3100
261 cu inch, sm420, 3.55 rear, torque tube still,omaha orange, still 6 volt, RPO green glass, side carrier spare, all done
In the DITY Gallery
Video of the 261 running

1964 GMC 1000
305 Big Block V6, sm420, the next cab off restoration