1969 Ford Fairlane draining battery

I have a69 ford fairlane gt with a 302 that im restoring and I leave it sit for a couple of days and the car wont start or even try after I jump it it will last about two days before it is compleatly drained ive bought a new battery from autozone and that didnt work so I got a new altornater and it still drains after. After I charge it I get out the voltage meater and it starts dropping allmost immedietly and ive run out of ideas does anyone know what is going on?