Multiple things need to happen for an engine to run:
----Adequate compression, that includes proper valve action and clearance.
----- spark, at the correct time,
-----fuel and air.
-----unobstructed exhaust (not plugged with walnuts, acorns, mouse chewins' mud dauber clay, etc.) (usually applicable to 2 strokes)
Did you set the points correctly?
did you check to see if the plug sparks while laying on a metal part of the engine while cranking over?
if not, check it.
Now as far as fuel metering= Carburetor.
An engine will run without a carb, it can, and has been proven.
All one has to do is dribble or squirt some fuel into the intake port.
Not carb cleaner, not starting fluid, not hair spray, but fuel.
You will not be able to control the rpm, or get it to run evenly, but it will start and run as long as fuel is provided.
Gives you something to think about instead of "shot gunning" parts till it is fixed, or one runs out of money.