Ive noticed in parts catalogs that they have different part #'s for the same things even though you would think they were exactly alike. For instance, the front fender extensions...are they the same or are they different in some manner? I'm going tomorrow to look at a 70 el camino to scavenge some front end parts off of it for my coupe like fenders, fender extensions and odds and ends. Anything thats different that i should watch oput for?

The front sheet metal will NOT work. The chevelle has different body lines. The fenders and fender extensions are different. Look at an online catalog, and they have different #'s for a reason. The only sheet metal I can think of that will transfer would be the steel inner fenders. Good Luck at the junkyard's, as you never know what you will find!

Jason,
The 70-72 2dr and 4dr bodies are TOTALLY different from wagons-El Caminos of the same year. Even where the headlight frame/parking light frame mates with the front of the fender is different. The specific reason can be seen at a glance. If you look at the sides of a 70-72 2-4dr, you will notice that there is a slight bulge at the front and rear wheel areas. This bulge is carried all the way to the front of the fender. Whereas, the wagons/Elkys retained the straight sides of the 68-9 models. Thus, the body side contours between coupes and wagons/Elkys is completey different and thats why the parts are different, even to include things such as the chrome wheel opening molding. BUT, things such as INNER fenders, grills, bumpers and hoods are totally interchangeable between 2-4dr and wagons/Elkys. So, if you locate a Cowl Induction hood on an Elky and want to put it on your 2dr, it will swap!
Hope this helps.