'74 Duster - stalls easily
So there might be a couple different Flathead screws on that carburetor. One or two of them can be for changing the mixture and another one for changing the idle. Just to be clear the one that changes the idle you can see it slightly pull on the throttle cable as if you're actually giving it more gas. The ones probably towards the bottom are changing the air fuel mixture. But everything on a tune-up starts from timing and fresh components as in cap rotor plugs wires and likely do you have points which I always recommend to do patronics which are more expensive to start but zero maintenance in the end...
(And please let's not let that start yet another debate this guy doesn't need it)..
Oh yeah and some new spark plugs and take a look at what the old ones look like..
Post picture of a couple...