The GN

[GATVILLE]

@MclarenGP

" If you don’t have the codes with you to indentify if it is an 8.5" or not, you can measure the distance between the very bottom bolt for the cover and the next adjacent one (either right of left), it will be 3 ¾" for a 8.5" and 3 1/4" for a 7.5".

 All 1978 and up Olds came with 7.5" 10 bolts, no 12 bolts (Chevy or Olds) whatsoever. So guys with 1978 and up G bodies had a few options: beef up the 7.5" with better axles and a good posi unit, or find an 8.5" out of an 83-84 HO, 85-85 442, or 84 and up T-Type or GN"

IS this saying some HO Olds had 8.5 inch? cuz the 442 was 85-86

iirc, all h/o’s had the 8.5, most were posi if not all. now, im not sure if all 442s had the 8.5 but i know some did.