A few questions from a newbie

[trimmy]

I am getting a 1986 chevy c20 with a 454 in it on saturday. The truck is in great shape for an 86 that has lived it life in Ohio. The truck when cold idles really high how do I adjust the carb(stock quadrajet) Can I and should I swap in a new carb without changing anything else such as the intake? My only plans for the truck is delete the emissions, put a set of header/mufflers and maybe an intake/carb then drive it. Its just a truck to run to lowes in and pick up firewood and and little projects. I am a total NEWBIE when it comes to gassers/carbs I am a diesel guy. Also the owner stated the truck does not switch from the drivers tank to the passenger tank what is usually the culprit?

Thanks for your help