Its also the angle of attack. Not to mention if the 'universal' one is 2 inches too long and the end only has 1/2" of adjustment before bottoming out, it's not quite so universal.
If you just have to have something cheap that may or may not work, just cut the stock wastegate, thread the rod and get a coupling nut from the hardware store.
or just stick a manual boost controller on the wastegate hose and be down with it.