89 firebird

i rebilt the top end of my 305 adding a new comp cam with a lift of 480.488
dur 258.264. i change it from fule injecton to a holley 600. i used a edlebrock perfomer intake and a set of 350 corvet heads that were ported.
and now i cant get the car to run right it sputters and want to die when i give it gas. it seems to idle just fine its very steady and smooth., but wont perfom in drive please help!

350 heads on a 305 could very well be the root of your problems. If the valves aren't hitting the cylinder bores 9a known problem with 350 heads on 305's) the intake valve is going to be severely shrouded and a lot of its flow is going to be useless. Also the combustion chambers on the 350 heads are for a 4" bore and the 305 had a 3.740" bore.