I just finished up this modification... and I considered doing what SVXCESS did with his fuse holder.
But I decided to do something slightly differently.
I mounted the fuse holder to my battery tray. (the plastic shell that the battery sits in, that has sides toward the engine, and toward the front of the car.
SVXCESS's car doesn't show that he is using one with his optima, and I imagine some SVXs may no longer have their original battery trays.
But if you do, I can tell you how I mounted mine. I have pictures, and I'll try to get them posted up tonight.
I positioned the fuse holder vertically on the outside of the tray wall. It is centered vertically, and mounted just slightly forward (toward the front of the car) of where the positive battery post is. There is a shape-change on the tray wall, and I aligned the fuse holder to sit right along side that.
It basically fits on the car between the oil filler cap, and the positive battery terminal.
Basically it is as easy as mocking up it's placement on the car, to make sure there is clearance...
Scribe the mounting holes of the fuse holder onto the plastic of the battery shell, and drill them out. (of course off the car, without the battery in the tray.
)
I then fixed the fuse holder to the battery tray wall with nylon license-plate frame bolts and nuts. Nice and non-conductive, and plenty stable enough to hold the fuse holder in place, and removable later, if necessary.
I fed the bolts from the battery side of the tray, with the nuts tightened down on the fuse-holder. The thin bolt heads don't impede the battery's placement at all.
The 4-gauge wire from the alternator fastens to the top fuse post, and then I made a ~14" 4-gauge lead from the bottom fuse post, that turns and comes up to meet the positive battery terminal lug, along with the starter lead, and the smaller lead to supply the fuse box for the rest of the circuits in the car.
I'll try to upload my clearer build-pics later.
The currently attached photo shows the finished work. The fuse holder is not visible, but it is down along side the battery between the battery hold down, and the positive terminal, in the space between those and the oil fill cap, and the AC pipe. There is clearance there without touching the corner of the valve cover.