I finally got my Optima Redtops to fit correctly, which took a little engineering so I thought I'd post here.
I had first heard of Optimas during my off-roading days and always meant to get one for my Toyota FJ-40 and never got around to it. The gel spiralcells are pretty much indestructible and since they don't have liquid acid in them they work much better at lower temperatures and you can mount them in any position. They also pack a lot of power.
There are a few different models, but I went with the 34/78. The 34/78 is a little on the small side compared to the Motorcraft battery, but the next step up in size, the 75/35, has 80 Cold Cranking Amps (CCA) less than the 34/78. I'm not really sure why, but I thought it would be best to go with the 34/78 since it is rated for 1000 CA and 800 CCA, which is a 50 CCA improvement over the Motorcraft battery. The small size and the difference in the terminal location does present a few small difficulties though.
First, you must use the "wing" adapters which snap into the bottom edge of both sides of each battery. They are included in the kit and essentially make the battery wider so that it can be clamped onto the battery tray. Next, the battery/intake cover on the driver side must be modified in order to accommodate the location of the posts. You could leave it off, but your intake would then be sucking hot air from the engine compartment, which totally defeats the purpose of the Zoodad mod if you've done it or plan to do it. However, any of the intake kits out there would negate the need for this because they eliminate said cover completely.
The cover is made of fiber reinforced plastic and is easily cut with a good sharp razor knife or a small hobby hacksaw. You want to score the FRP with the razor knife as you would sheetrock, and then you can bend it a few times and it will snap off clean. Afterwards, use some 120 grit sandpaper to round off the edges for a clean, factory look. Here's what it looks like when its done:
Note in the installed picture that I made a small (about 1" by 3/4") notch near the positive terminal in order to make room for the terminal/protective boot:
The wire seen running into the battery compartment is the 8 gauge main power wire for the fuseblock under the dash which feeds the Sirius receiver and the Pioneer stereo. One other reason the Optimas are nice is that they have two sets of terminals, the regular posts, and the GM style screw in connections. This is what the stereo power wire is connected to via a gold plated screw in stud I picked up at Autozone for $3.00. The extra terminal simplifies stereo wiring a lot and simply makes it look cleaner.
The passenger side of course is much easier with one small snag. For some reason the passenger side terminal (which is a junction of three cables) has plastic "nub" on the bottom which I think may be intended to keep the terminal from twisting because on the Motorcraft or any similar sized battery it locks against the side of the battery case. This nub is easily removed with the same small hobby saw you cut the battery/intake cover with. Now the terminal will fit nice and flush. As long as the terminals are properly tightened they shouldn't twist. Also, the Optima is too small for the blanket to fit properly, so I just left it off for now. I doubt its even necessary since the Optimas perform so well in the cold, but I may trim the blanket and refit it with some tape this winter for the hell of it.
So far I've had them in for 4 days now and the truck starts quicker than when I first got it. I'll keep everyone posted on how they do once it gets into the single digits up here.