305 tbi on an older 350 motor??

I just put an 81 350 in my 89 chevy truck that had TBI. I put the TBI on the 350 with an edelbrock in take and a adaptor plate to put the TBI on the 4 barrel in take. right now everything is hooked up except the O2 sensor and it starts fine and idles but if you give it some gas or just start to go it runs like crap. almost dies. but if I give it full throttle it runs pretty strong. but when you get up to speed and the rpms drop down it runs like crap again. I keep adjusting the distributor but it doesn't change anything except the idle. I'm tired of putting money into this and I really don't want to go threw the process of changing it to a carb. and having to buy a fuel regulator that will work with a return line. How can I get this to run good with out dropping to much money???305 tbi on an older 350 motor??
The problem is that your 81 intake manifold is a dual plane design and those two little fuel injectors cant send the fuel down all of the intake planes equally. IF IT IS NOT caused by a massive vacuum leak or plugged fuel filter. You need another manifold (I ve never seen one to covert an old carb engine to throttle body but if it exists www.jegs.com will have it or can get it) ONE LAST THOUGHT check your map sensor and make sure its getting proper vacuum305 tbi on an older 350 motor??
Your EGR valve is bad, I would say that your spark plugs are fouling out too. And the motor is loading up on gas and the fumes burn your eyes and the exhaust is blowing black as soot, am I right......than your EGR valve is bad! Let me guess when you turn the distributor until it runs smooth you don't have any power and the motor coughs and sputters when you give it gas,and when you trun it back the other way you have power but the motor runs rough!
The original TBI intake manifold should bolt right on the older engine. the manifolds didn't change till they went to the vortec engine. It should work. You do need the oxygen sensor though. that can be causing alot of your problems. I would start with that and if that don't help put the TBI intake on it. And also you need to set your timing with a timing light. They are critical on timing.
check vacumn leaks under tbi wrong intake ?
when you bought edelbrock manifold did it have instructions on where to put o2 senors ? as this sensior controls inject system most times o2 sensor is in exhaust manifold or pipe before cat if wires left unpluged computor can not tell inject and ign timing what to do so if you use headers on left side there should be pipe plug thread for o2 sensor useing restor is not a good cure as sensor resistance changes as load on engine changes exhaust temp not shure if old intake manifold will work as it set up for 2 plane tbi use plumemm chamber intake i think if your state emissions will let you go carb engine and distrib get trans shop to make trans shift with out computor but if not you need intake from tbi engine and distrib i have never tried useing older engine to tbi i most times go other way late model engine to early car but let me know if you need more info