actually better get new front bearings right and left, pack em with grease , pop em in, and at that time examine rotors, calipers, and pads and after installation hopefully vibration will be gone. If not can at least eliminate brake system, and then move on to tie rods ends and more trouble shooting.
any suggestions on bearing replacment? shall i get from chevy parts department , or does anyone know of a better bearing to purchase and install?
Well before you do all that, get yourself a dial indicator and a magnetic base. Take the right wheel off, caliper off, mount the dial indicator and magnetic base to the spindle and measure the rotor runout. GM FSM says .003" is the limit. Mine are warped .0035" and you can feel it under heavy braking.