That's a good learning experience, but not necessary, because you don't need to know the compression stroke until you set the rockers or put the dizzy back in, and at that point you will have rotated the engine over anyway. Plus, since you have it apart it's easy to see exactly where the rockers and cam lobes are, so you can watch when you are on the compression stroke. Just relearn your 4-stroke cycle and you will know when its on the compression stroke. Intake-compression-power-exhaust. So after the intake closes and the piston is coming back up, that is your compression stroke. However, you do not need to have it on the compression stroke to measure TDC. TDC is exactly the same spot whether it's after the compression stroke or the exhaust stroke. Just use the piston stop and you are good.
About the cam, what is your cam now? Different heads without a different cam is like choking the new heads.
Tha finger on the plug hole trick is a great way to find the compression stroke if you have to put the dizzy in and don't know what stroke is the compression stroke. Because if you put the dizzy in on the power stroke your timing will be 360 degrees off(or 180 dizzy degrees) But if you are simply replacing a dizzy its easier to mark the rotor when you take it out.
Clean everything real well. Gasket surfaces should be spotless. Also, check the block deck for flatness with a straight edge and feeler gauges, I wouldn't reassemble if its over about .002 gap anywhere.
If you do the cam you will need to pull the balancer and oil pan, and timing cover. Plus I would degree the cam, but not necessary.
Anyway, assuming shortblock is complete, and everything is clean and inspected...
Bolt on the heads and torque them. Torque them in 3 stages, starting from the middle of the head and working out in a circular pattern.
Add pushrods and rockers (just loose)
Now rotate the engine over until after the #1 intake valve closes and the engine is at TDC on the timing mark. This is the compression stroke, both valves should be closed on #1 or you are not at the right spot.
Then feel the pushrods (spin them or move them up and down to feel it)and tighten the rocker nut until there is zero clearance, then tighten another quarter turn. Do that for the intake and exhaust valve rockers.
Then rotate the crank over 90 degrees (clockwise from front of engine, or tightening the balancer bolt, just guess a quarter turn, close enough), then adjust the #8 rockers the same way, quarter turn past 0 clearance. Then turn the crank 90 degrees again, and adjust #4 rockers. Continue to do this and adjust the rockers in firing order, 1-8-4-3-6-5-7-2. You can double check you are back at TDC when you turn it 4 times, and are checking #6, it should be on TDC again or your quarter turn guesses were a little off, but its likely not a problem, just recorrect and continue the other half. It makes no mess and the rockers are good before you start the engine.
Once that is done, put the valve covers and intake on, etc.
Precisely, you are basically marking the same point on both sides of TDC, and exactly in the middle of there is your exact true TDC.
Thats not accurate enough, if you watch teh piston at TDC you will notice dwells there for several degrees before going back down, and you want to know TDC within less than 1 degree.
Yes, some people use dial indicators to find TDC. However, they still don't do it at TDC, they mark the piston .100 down the hole or something and then do the same on the other side and still use the middle of the marks.
However, its much simpler(and more accurate) to use the piston stop method because it gives you a positive stop that will not change, so you don't have to worry about being off .002", or that the piston may have rocked in the bore, etc. It will stop at the exact same location.
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