[Longhorn Man]

try lube first
either a worn hinge, or worn rivits can cause this.
A good way to adjust for this (if parts replacement is not in the budget) goes like this;
Grab a friend...doesn't have to be a mechanic in any way shape or form, the most non wrenching SOB will work fine (even the wife will work if you can convince her to help)
Open the hood, and loosen the 3 bolts on each hinge that bolts to the inside of the fender.
Have your assistant push up on the hood, as if they were trying to open the hood further than it is supposed to be. While they are doing that and holding it, you run around with your 9/16ths socket and rachet (with a 6 inch or so extention) and tighten the 6 bolts again.
Now, SLOWLY close your hood. The nicer your paint, the slower you'll want to go. You need to keep a close eye on the rear edge of the hood, make sure the hood doesn't pinch the cowl panel. If it does, then you'll need to loosen the 4 bolts that hold the hood to the hinges, and pull the hood forward. If it doesn't hit the cowl, then you'll need to make sure the latch pin goes into the latch. Once you confirm it will go in the hole, and the back clearance is good, slam the hood and enjoy the 'fix'.
*note*
you can go too far, and have to redo it again, and you may find one side is worse than the other.