No reason your carb shouldn't work at altitude. When you say " put all my stuff on " what exactly do you mean? Did you mess with anything electrical? It does sound to me like you've got a float bowl either starving or flooding, check the float level,needle and seat.
Did you obtain this vehicle from a high altitude part of the country? You may just need to re-jet your carb, or do as the others have suggested and adjust your float and idle air mixture. Messing around with carbs isn't rocket science, there's a method to tuning. Once you get the correct method it applies to most normally asperated, carb'd engines engines.
I have to agree with Zuki Girl on this one though. It's probably gonna be easier, and have much better all around results by switching to a Throttle Body Fuel Injection off any old Trackick 8 valve. Grab the intake and everything from there up including the wiring harness and ecu.