i looked at the FAQ section and now need some help

does anyone know want set of speedo gears i need to correct my 90 rs with factory 2.7 stock rear to 3.27 and maintain stock accuracy?

if any know the exact combo i would be verry pleased.
3.27 is high enough for my purposes.

edit maybe i phrased this too weird.....
i'm installing a posi rear with 3.27 gears
i want to keep my speedo correct what are the stock
speedo gear numbers...closest to that on FAQ section was the 3.31 gear set