I have a quadrajet carb off of a 1984 chev 1/2 ton 305ci. engine. Worked great when i took it off, but when i put it on another 305ci. in a 1985 olds cutlass i can get it to idle awsome and start great like it always did on my 1/2 ton, but i can not keep it running a wot or even 1/4 throttle in gear. It sputters, bangs, farts, and dies on me. I have good fuel pressure. My vacuum gauge is reading 18 to 20 pounds at idle. The timing is at about 12 degrees advance and i use the vacuum port on the carb that always has vacuum supplied, not the switched vacuum port. When i juice the throttle and let off it tends to slowly die out n stall... sometimes. Before the car was stolen it had a carb off of a factory 81 camaroZ28... 350. It always started and had allot of snap off the line, but if you did not let it warm up fully the choke would cause it to run like a pos. When the stole it they did not let it warm up and i could not get it to stay running in wot. (the engine has about 100,000m on it and has a new chain with the cam advanced 4 deg. all the rest is stock. The engine does not have any knocks at idle but at about 3000 rpm it sounds like a rocker is loose but then it will go away when it was running.