Compression Stroke

The dots have NOTHING to do with the compression stroke ....... until you correctly install the cam.

You yourself have to positively locate the Crank to TDC#1,
Prior to installing the timing set,
that has been previously meticulously aligned dot to dot.
If the top sprocket does not fit, you have to rotate the cam until it does ........ without moving the crank sprocket.
After
this is done, you have to verify the crank is still at TDC#1, and the dots are still aligned.
After that is done, you should be able to slowly rotate the crank two full turns with no valves getting slapped by any pistons.

But you really don't know if any marks are accurate.
To sleep better, I would still figure out where "split-overlap" is occurring, relative to #1 TDC. Split overlap is when both valves for a given cylinder are open the same amount. The window for this to occur is about 4* retarded to maybe 8* advanced, and you want to be somewhere close to, in the middle of that.
On an SBM with hydraulic lifters, this can be a tall order, and
if you don't do it, it's no big deal; if the sprockets are accurately marked.

Before you put the distributor back in, make sure #1 cylinder is at TDC compression. Then back the crank up to say 10 * advanced, then stab the D in with the rotor ending up under the #1 Tower, and continue.
Good luck.