Wierd fuel pressure and hard start issue

This is in my 70 D200 with a 383. After setting for 4-5 days I have to crank and crank. I've checked the carb and there isn't any fuel when the throttle is pumped, hence the crank and crank. I rebuilt the carb and replaced the fuel pump. I checked the fuel pressure today and it was 7-8 psi at idle. Here it the weird part...After shut down the pressure climbed to 12 psi. I've never seen this before and I suspect it is overriding the needle and seat letting the fuel overflow the carb. Any suggestions or questions to figure this out. Thanks Craig