Weird radio recption problem 90 MM

I have a '90 Mighty Max 4X4 that I'm restoring and I put a brand new Pioneer CD radio in it and it works, but I get horrible reception. I put a JC Whitney radio antenna booster and a electronic windshield mounted antenna in the truck and it still gets horrible reception. I live right outside NYC so I'm not far away from major stations, the radio is grounded right to the dash frame, the dist. cap and wires are new and not creating any interference, every relay and switch has been replaced with new yet I'm still not getting good reception. I'm hardly an idiot when it comes to audio work, but this is perplexing me (annoying me too). Has anyone else ever dealt with this from these trucks or have any ideas on what I'm overlooking ? I appreciate any help, this is driving me nuts

Have you tried that radio in another vehicle? It might not be your truck.