Carburetor sizing??

I’ve got a 64 mercury comet with its factory k code 4 barrel 289 and factory autolite 4100 600cfm carb. Every time the car sits for over a week the floats stick and it floods bad. I’m done messing with the autolite and planning on going with a edelbrock carb. I’m planning on putting a 500 cfm avs 2 and a fuel pressure regulator to go along. The engine has a lot of miles and honestly needs a rebuild pretty bad so I figured there is no reason to need 600cfm. My plan is to drop the jet sizes for my elevation (5000 feet) and put some slight metering rod springs in to account for worn rings hopefully I’ll have a good cruiser engine until I can eventually drop the crate engine into it I’ve been planning on. Does this set up seem like a good idea?