I am having problems with the hood latch on my 80 vette - latch doesn't want to lock, unless you slam the hood.

You need to adjust the latch pins in the hood.  Make them longer to allow the latch to operate easier.  What you will need to keep an eye out for is the level of the hood once it is latched to ensure it doesn't sit too high and looks out of line.

The '80 cars have a different latch set-up than ours, Chip...no pins. They have a round bar that the latch catches on, similar to the door latch set-up. The hood latches are "adjusted" with shims...

You may lube the latch assys with some spray lube first, to see if that helps. Also, make sure your hood release cable is returning to the closed position when you release it. If the cable is binding/dragging, it may not latch the hood when you close it, unless you drop it hard.
I think most of us have agreed that dropping the hood from about 12-14 inches is the best way to get it closed/latched. Adams' Apple2007-01-28 15:26:39

Hey thanks for the advice guy's!

You shouldn't have to "slam it" down to close it.  Just letting it free fall from that height should be more than enough to engage the latches.

On my '80, I had to slam it until I discovered I had to push in the release handle every time.  I can't get it to return on its own.

I have new cables and still have the problem.

I have found that if I gently set the hood down on the latches and push each side gently down till it latches, it doesn't jar the hood as much as the drop from 12" to 14".

If you decide to change out the cables, be wary of the ones from the major suppliers.  the molded plastic piece that screws into the metal tabs to hold it in place will come loose from the cable itself, not allowing the cable to open the hood.  Most are way too long, so you can leave it loosly laying behind the distributor by the channel of the firewall so you can reach in and pull it if need be.

I never slam my hood because too many people have told me it might crack the hood or stress the paint.

[QUOTE=Adams' Apple]The '80 cars have a different latch set-up than ours, Chip...no pins. They have a round bar that the latch catches on, similar to the door latch set-up. The hood latches are "adjusted" with shims...
[/quote]

DNV is WAAAY right... if you get a new release cable, get it from your Chevy dealer, the aftermarket rigs are JUNK!! I have a '78 and have gotten in the habit of pushing it back in after I pull the hood release.

Dave