Vibration in driveline 2005 Tacoma TRD Sport LWB

I have 2 questions first is I bought a set of 16" polished aluminum rims with 225x70 bridgestones as my truck is always on street . I didn't try them on and they contact the front Disc caliper.( THEY ARE GENUINE TOYOTA TACOMA 16"x 7") Reason I bought them to replace my 17" Is the 17s are made in Canada aluminum but are spray painted silver. Also because since it was new there has always been a vibration in driveline between 45 and 55mph .Since my truck only has 70k on I thought I would try the smaller tires.Is there anyway to use spacers to let the 16" clear the calipers, and do you think this solution might help with the vibration. Thanks in advance for your help!!