OK IV READ THAT ALL OLDS HURST/442 CAME WITH THE 3.73 GEARING AND 8.5'' REAR END BUT NOT ALL HAD POSI. POSI WAS A OPTION TO BE ORDERED AS THE G80 OPTION, IS THIS CORRECT? IS THE G80 OPTION FULL POSI OR JUST LIMITED SLIP? I HAVE AN ORIGINAL BUILD SHEET FOR MY 1987 CUTLASS 442 AN IT SAYS G80 LIMITED SLIP. IM CONFUSED. ISNT IT SUPPOSE TO BE POSI?