57 Buick special power steering pump whines when turning even when completely full

[Frank Falconeri]

I'm considering to install a modern stereo system in the old girl, I believe this car originally came with radio delete ( no antenna ) the previous owner put an original radio in the cavity bit just to fill a hole and not hooked up to anything. I noticed a speaker grill above the radio in the dash, the rear deck has one factory cut out for what looks to be a 6×9. Has anyone updated their system with 4 to 6 speakers, amp and so on and what would you recommend any thoughts on this would be greatly appreciated