Are the Xigmatek website specs right? 150mm(L) x 160mm(W) x 86mm(H).
150mm (5.9") and 86mm (3.4") are the standard width & height for an ATX PSU - which makes more sense than a non-standard width.
It's my guess the Xigmatek PC-702 PSU is the same width and height as any ATX standard PSU 5.9" (150mm) x 3.4" (86mm).
And at 6.30" (160mm) its just a bit longer than a basic PSU so there should be no problem with it fitting in the CM Elite 330 case.