Be sure your butterflies open freely, all the way to WOT, after its bolted down. Sometimes the butterflies will bind against gaskets or intake. Second, make sure you have all the linkage adapters to include a kick down for the tranny (depending on what you're running). You will need to re-config your fuel line setup, that also requires different fittings.
BTW, the stalling at the stop box is typically fuel flowing out the vent tube into the carb. Extend the vent tube with a short piece of hose, or connect the two vents and cut a small hole in the hose. This will keep the fuel from sloshing out the vents. Another option is pick up your idle to 900+.
BTW, the stalling at the stop box is typically fuel flowing out the vent tube into the carb. Extend the vent tube with a short piece of hose, or connect the two vents and cut a small hole in the hose. This will keep the fuel from sloshing out the vents. Another option is pick up your idle to 900+.