I have an 88 n/a with a 91 n/a motor only swap.
I also have a crap aftermarket head unit.

I am getting a high pitched spinning noise coming in through the speakers that is directly relitive to engine speed.

how can I kill this sound

 

You need a better grounding point for you stereo. Also if you have taped wires this will happen.

 

Tapped or Taped? I dont see why tape would make a difference, and its not taped anywho

 

Better grounding.