carburetor swap help

i have a feedback carburetor on my car and i came across a non feedback carb....can i still use the non feedback one or will it mess things up by not using the electrical things

If you are referring to a fuel return to your tank u can run without that, but if you are talking about a dual feed to ur carb, no u need both in order to get full throttle. I would like to help you out some more but i need to know more info, carb, fuel pump style/set-up. Help a helper out.
http://files.automotiveforums.com/gallery/watermark.php?file=/503/25420969Firebird_5_-med.jpg

both carbs are quadrajets but the one i had the plug in with the three prongs andanother plugin near the choke but on top of the carb

What kind of car is it? Year etc....
What engine??
It sounds like you have an electronic Q-jet, and i think you are trying to swtich to an older model from what i am gathering. If thats the case the only way the older style Qjet would work would be if you went completely mechanical as far as the ECM goes.
I would like to be able to help more but i need some more specific information. I hope i have given you some direction. Please let me know more so i could help you better.
http://files.automotiveforums.com/gallery/watermark.php?file=/503/25420969Firebird_5_-med.jpg

i have a 1984 z28 and it has a 350 in it.....i put the new engine on in the fall.. there was a electrical carb before and i have a older one now.. what would i need to change for it to work? as for the manual ecm.

are the rest of the "idiot lights" hooked up or are you using all mechanical devices for the new engine. If its all Mechanical no problems. If the ECM is still operating it wont run at optimal performance. But you said the engine was changed I dont believe it will affect anything.