i just bought an 80 el camino with a 355/350 combo.  i don't think the motor is original and it's also got an edelbrock carb(?size?) but the kickdown linkage is not hooked up and i don't know if i need to get a new bracket assembly and/or a new cable(it looks like the current one is too long)  

You should have the kick down cable hooked up. There should be a bit of adjustment that you can do (on the carb end). Maybe an aftermarket cable will work better for you as they have alot more adjustment in them and run 25-50 bucks. An Edelbrock carb should be able to do a direct hook up. As far as carb size thats an easy one. Stand in front of your elky and as you are looking at the front of the carb, there will be a four # digit (like 1406 1407 1411) on the bottom left of the base plate where the mounting stud is. The # is stamped and will be just above the intake manifold. Post it on here and I or some one will tell you what size you have. I like the elcaminos and had a 76 with a slightly built buick 455 in it.  

my carb number is 1406  

Edelbrock makes a relatively cheap bracket for the kickdown and throttle cable all in one.  I believe it is part #8036...I think.   I would also go with a new adjustable cable.  Should be able to snag one at about any tranny shop.  It lets you adjust the mounting point for the "carb" end of the cable.  All you need to do then is adjust it so the cable is at full extension at Wide-open-throttle.  

that is the 600 cfm model. should have an electric choke if i remember right