2 problems can anyone help?

I have recently bought bought a 3.9 v8i 1994 auto model which had just had a distributor rebuild and new lamda sensor but every now and again it idles unevenly hunting as my dad calls it, also sometimes driving along you can put your foot down and nothing happens, but pull over and the engine seems completely normal.

The other is when driving above 20MPH i can hear a faint mettallic noise coming from the passenger footwell area i presume its to do with the wheels going round its just had new brake pads so i know its not that. It actually sounds like the blower is on the lowest setting coupled with a metallic sound.

Can anyone help thanks rob.