OK, You should set the shortblock with #1 at TDC on the firing stroke.
Ensure the lifters are all greased with assembly lube, as is the cam. :!: Remember that cranking the motor before it starts up, is wiping a lot of this off, risking damage to the new cam.
Verify your ignition before installing. Do this by hooking up the dizzy and coil etc, but not installing the dizzy. Clip a ground lead from the distributor case to the block or body. Power up. Now spin the dizzy with your hand twisting the drive gear, and see that you get a good healthy spark out the coil lead.
Now install the distributor with the rotor button lined up with #1 terminal. This corresponds to the piston position set before, so you are sure it will fire easily.
The head can go on. After allowing the correct relax time between torque settings, install and adjust the rockers. Use assembly lube to both ends of the pushrod, and on the rocker arm wear surfaces. The correct setting for a lifter in this case, is with no pressure, give it a few minutes to fully extend. Grasping the pushrod between your thumb and first finger, you should feel a little slack as you try to jiggle it up and down. The assembly lube will make this feeling a bit claggy.
Tighten the adjuster until you can no longer feel any up-down motion possible. Now add one full turn. Do this separately for each of the inlet and exhaust on #1.
Now, if your valve stem tips are within say 60 thou of each other in height, you can cheat. Measure the amount your rocker ajuster protrudes from the arm after setting, and copy this measurement to all the other cylinders.
That's the presets; don't overtighten the rocker cover and use a sealant like Permatex to hold the gasket in.
Now, you need to be sure the carb works. Use a carb from a motor you heard running within the last few days. Once they dry out and sit, problems increase in potential. Fill it through the bowl vent, and verify by tweaking the throttle shaft. As only the head was off, not the whole motor apart, there's no real need to prime the oil supply.
Check your electricals again, connect the radiator up and fill with coolant. Check your oil for contamination, and level. Use non-synthetic oil for the break-in period. The motor should now fire up without any hesitation.
Run it at 200RPM without any speed variation, for a good 20 minutes. Monitor the time elapsed. If you have to stop it, next restart should be at the same speed, for the remaining time.
After that, check your lifter adjustment and oil, and it should be able to run a few miles before dropping the oil and filter.
See! Simple.
