Hello, I am putting together a 73 el camino as my first car. It is missing a lot of interior parts, a few exterior parts, but mostly little things, the emblems, heat vents etc. I was wondering if the parts interchange between the two years (77 el camino to a 73 el camino), as I know they are in the same generation. any help would be greatly appreciated. Thanks

 

1) Only your large local junkyard, with their parts interchange catalog, knows for sure.

2)Generally automotive design engineers hate to leave ANYTHING unchanged for five(5) years.
They make more money by constantly changing everything for no good reason. So the short answer is probably not, but you may have to go on a part by part basis.