Just change the choke pull off and make sure any questionable vacuum lines are replaced. The tension for the secondary door is set too light. I find this on every Qjet I come upon is that way. It just requires an Allen key and a small standard screw driver and will eliminate a secondary bog. Don't go with a Edelbrock carb, they usually run terribly on an Olds and will need major retuning on a 307. Headers can be a PIA to install. But headers and duals on an Olds add 30 HP, it has been dyno proven on Olds 350's and 455's. On the 350 and 455, the better Thornton manifolds were used on that dyno run, showing full length even a bigger gain over regular SBO manifolds. Those swirl port manifolds are particularly bad for flow, along with the factory crossover pipe and single exhaust. An O2 sensor bung will need added on any aftermarket system, I would also do the heated O2 conversion, especially with headers. You could go with Thornton manifolds and custom dual exhaust. A 2.25" system would be plenty big enough. You will need a dual hump crossmember with full length headers. A custom bent 2.5" dual system can fit all under the passenger side hump, I had one done. Thornton and Sanderson also have shorty headers. Hedman has a shorty that is more of a mid length, it makes exhaust routing more difficult, the collectors point straight down. The Hedman are the only cheaper full length headers worth buying. What transmission does it have? The TH2004R overdrive will allow a gear swap that will make your car feel much faster and highway rpm will still be acceptable. Good luck.