Looking at www.kia.com and www.hyundaiusa.com, the 2.4 in the your Optima
seems to be the same one that's used in the '06 and newer Sonatas.
All the listed specs are the same, but I cannot find any mention of the
method of camshaft drive on the Kia.
My guess is that it's basically the same car as the '06 Sonata 2.4. So
you won't need to leave.