Upper Control Arm bushings??

My ITA 83 Rx7 has upper and lower control arms in rear. It only has bushings on lower arms. I hear a very loud banging when I give car gas, shifting ect. I figure the uppers are supposed to have bushings too, but I wanted to make sure if anyone new for sure, or a good place to order them. I just bought the car for drivers school so Im just realizing the problem. Thanks for any info.

we need to know how much the rear suspension has been modified. it is common pratice to at a tri link which is a traction control device that attaches to the top center of the diff and runs forward to the body or frame and a panhard rod replacing the stock watts link. if the car has these the upper link bushings have to be removed usually replaced with foam rubber. if you do not have a tri link yeas you need bushings in the upper links.
dick