In what an 88? I know the later ones needed a 23 tooth (white) but that was for 373's and it was pretty accurate....Your speedo shouldnt be that much off with 390's and the 23 tooth gear.With 410's its way off..
in what an 88???
i dont get wha tyour said.
Its an 8.8 rearend and it has 3.90s gears in it. It will bolt right up...
so a 23 tooth? are there any in-between gears??