Truck won't start
 

I have a 1977 f-150 with a 351 modified with a two barrel carb it's my daily driver and it wouldn't turn over, this has never been a problem even in the cold it's in was in the 40s this morning and I was Frantically trying to get to class so I took my extra car. When I get home what should be some things I should look for?

So we are all on the same page,
When we turn to start the engine , it cranks/turns over before it starts up running.
There can be times it won't start, turn over /crank. It's either one of these or it starts and runs/ fires up.
If you can please as specific as you can and tell us exactly what it is /is not doing.Thanks.