Just wanted to know if it was o.k. to use ceramic pads in the rear and semi-metallic in the front?

I had new front semi-metallic pads and just needed the rear but they said they only had ceramic for 20 bucks

i asked if it was o.k. to use rear ceramic and semi at the front they said it was fine but i just want to make sure

its for a 91 na single piston brakes

 

No. It will totally screw up the brake feel and bias. Keep pad types the same unless you really know what you are doing.