is it another ib5 box your after, just looked through the good old haynes for ratios of the boxes and the ratios go upto 4.27 witch is close the next is 4.06, not 100% on witch ratio is the 4 speed for the base 1.3 or the 5 speed for the 1.4, they are front mount starters, but different driveshafts as they are 23 spline instead of 25 for the higher ratio boxes, not sure on shaft thicknesses though, i'm breaking my 5 speed 1.4 by the way