it's always hard to diagnose a sound when you can't hear it,but same as Sean above^
I'm not liking the prop is 20mm further in the g/box either, could try undo center bearing and check if the prop can slide further into g/box
or if it can't it's bottomed out on the output splines and you need a shorter prop rear half
abs and non abs 13's have longer short props , abs diff nose is longer/prop is shorter, possible car was N/A had open diff OE ?
180sx in s14 section with a 13 diff has confused me a tad,