I have a 1980 with the single headlight grill but I want to swap it for the later stacked headlight style grill will I encounter any problems? Or is it a straight swap???

Sorry if this is a dumbass question im new to caminos!!!

There was no stacked headlight front end for 5th Gens; only the "Laguna" front end had stacked headlights and will only swap on to 4th Gen El Caminos.

If you swap to an 83-87 header panel, you have to put on the later fenders with the side lights to be legal. I doubt it is enforced, but it may cause a problem if you have to have the car inspected

The radiator support is different from 82-87 to accommodate the extra headlights. In addition to the header panel and wiring harness, you'd have to either modify your existing support or swap it for a 82-87 one.

Ok thanks for the help guys.

I've done several of the conversions and they are not difficult. You do need to do some wiring because you need four headlight plugs, not just two. You'll need the complete header (front) panel with the headlights, turn indicators and grille. Your bumper will work just fine. You also need the core support to do it properly. The core support is the panel that has the hood latch attached to it. It goes from fender to fender and looks like it would be a bear to swap, but it is not. The late core support has areas to clear the four headlights that the early one does not. You could probably do some surgery on the panel to make it work.
As far as the side lights are concerned, I did have to have 'em to pass inspection in Hawaii. So, I bought 2 small truck clearance lights, and attached 'em to a small piece of aluminum so they could tuck into the front spoiler like a bookmark. I ran the wires with quick disconnects, so after inspection the whole mess came off. But that was back in the days of plain round or square glass headlights. Now, headlights come in so many shapes and sizes that the side lighting is built in to them. Nobody even checks anymore.