The performance HAS TO BE better than the stock extended one, otherwise i will be a looser.
There is no welding in the rear shaft. The stock lwb vehicles' shaft is 1.5" longer than my this extension (the original lwb vehicles are 13.5" longer than the swb vehicles whereas i extended it to 12"). But at the same time the bigger shackes needed a little larger rear shaft so i fixed the original samurai lwb rear shaft and it's "sooter by sooter" perfect with zero% vibration and was as smooth as any lexus around.
And it all depends on how you have done your job. In my opinion if one works properly keeping in view ALL TECHNICALITIES in consideration, the project has to be better than the stock vehicles which were made 25 or more years earlier.