Is it possible to convert from auto trans to a manual trans in an 83 RX-7? I read somewhere the engines are different but I cant hardly believe that.

No, same engine. You need a new flywheel, counter weight, clutch, clutch pedal assembly, clutch hydraulics, tranny, driveshaft, and interior pieces (ie. shift knob surround, and if you really want, but not necessary instrument cluster). Plus, loose the tranny cooling system (which depending on your set up, might mean a radiator)... That sounds harder than it really is. The hardest part is getting the pieces and changing the pedal assembly.