Thunderbird v8 is making a whistling noise? Could it be the air conditioning compressor or the lift tensioner.
It could be many things. Maybe a vacuum leak. Check it out with a mechanics stethoscope.
Doubtful about A/C or tensioner. Far more likely vacuum, like he said even direct intake manifold leak, not necessarily a hose
Search Ford Thunderbird Questions
Are you a UK consumer? CarGurus now has a discussion forum in the UK.
Ford Thunderbird Experts