I went to pull my 79 out of the garage to give it a spring cleaning... went to crank her up... and it just cranked and cranked but never started. After some trouble shooting with kstyer on the phone, it seems the trouble was a stuck check valve on the fuel filter.

The first thing I did was held the choke open and looked in while hitting the throttle to see if gas was entering the bowl.  It wasn't. Next I loosened the line from the fuel filter and cranked it a couple times to see that fuel was in fact being pumped to the carb. It was.  So I pulled the fuel filter out, being careful not to lose the spring inside the housing, and the clear plastic ring that goes around the housing.  I pulled the check valve (black rubber with a white plastic round piece attached to a spring) out of the fuel filter. Pulled the spring and white plastic piece out of the black rubber.  Smushed it a few times with my finger, put it all back together.  Worked the piece up and down a few times with a small screw driver.  Installed it back in place, and the engine fired right up.

Seems to be good for now.  I'm going to have it out all day tomorrow, so we'll see if it is fixed for good.

I usually pull the valve out and throw it as far as I can... Keeps problems like that from happening.
The purpose is to keep the fuel from draining back out of the bowl once you shut the engine off, but the only thing it really does is restrict the fuel flow.

btw..is "smushed" a technical term for squished?
I'll need to make an annotation in my service manual...

Glad ya got it running.

I usually leave the valve in a new filter, but not always.  If they give me a problem, out it goes.

So I had it out yesterday...
No problem starting up in the morning.
No problem starting up at lunch time.
No start in the evening.
I took the check valve out, and it started right up.  The check valve has gone bye-bye!

Some types of fuels will react to the "rubber" part of the little valve in there, and stick it. Then again, it may just be a bad filter to start with.
The only real drawback to removing the valve is it might take a while to start the car if it sits for a few days without running, as the fuel can run back out of the bowl. You would think that if the float was right, then the needle would be seated in the carb, and fuel wouldn't be able to flow back, but...fuel evaporates, the float drops a bit, and there she goes!

You might try getting another filter and installing it. The one you have now may just be defective or something.

I wonder if the problem is related to the fact that the fuel flowing through there right now has been sitting still in my tank for 6 months. It is almost empty now, so the next time I take it out, I'll fill it will fresh fuel.

Might throw in a bottle of dryer (HEET or some other brand) to clean any water out of the lines.  Getting the level down too far could clog up the sock with junk from the bottom of the tank (I hate it when my socks get clogged from stuff out of my bottom) 

Glad it's up and running!

I doubt 6 month old fuel is the problem, or even related, unless it was crap fuel to start with.
My car sits FOREVER without driving, and it fires up every time, no matter how many years it's been sittin.
You prolly just had a bad filter.
You could have some crap in the tank, fer sure, as Dennis suggested. I put a new tank in the '74 a few years ago(2001 or so), and I can look down in it and see water at the bottom. Not a lot, but it had to have come from the gas station tanks.

Do they deduct points at NCRS for cars that run on water?