just like the new thing for rubis and 05+TJS THIS JUST TAKES SPACE OF WASTED SPACE THAT HOLDS OUTPUTSHAFT OR AM i WRONG
nope - the output shaft of this doubler replaces the input shaft of the t-case for Dana 300 or 20 so it turns out to be shorter than the klune - has nothing to do with the rear d/s output shaft but for example with the Dana 300 + this doubler which is 4'' you are probably close to the same overall length as a stock np231.
EDIT: i didn't see anything being mentioned for the stock 231 so i assume they won't have an option available for that but in case they do then i guess with a super short SYE would be the same length as the D300 or Atlas combined with this black box.
looks really nice btw, i would love one but it's $2k, not cheap imo but a fair price though.