My wifes 78 has a gas like smell in the cockpit while driving. I have followed the gas line from the tank to the pump then to dual imputs on the street demon. No leaks to be found. It started after I put a new 10" x 2" edelbrock air cleaner on and painted the hooker headers.I can't beleive the paint would still be flashing off after 3 weeks yet only 60 miles. Any ideas?

It could still be paint. But also check that the PCV system, including the breather air inlet, is still functioning after installing the air filter.
Don't overlook unrelated items, like cracked hoses at the tank.

This engine has no pvc set up. Both valve covers have breather caps. And as far as I can tell the demon has no pvc port on it. The air cleaner has a port on the base which I pluged.Didn't want dirty air getting in. The old air filter was the edlbrock 1000cfm triangle unit with the foam filter. We live on a dirt road and wanted pleated fabric for better filtration.

No PCV of any kind is a bad idea. The only thing that vents the crankcase is pressure. This means the moisture and acids that build up do not get purged. This shortens both oil and engine life. You may want to reconsider. PCV can be done with a pump or by connecting to headers, if you don't want it going into the intake. You should have something. And yes, you could get fumes in the car from your set up. You might not, but it is possible. You could just run a hose from where one of the cap are to the bottom of the air cleaner. Not good, but better than nothing.