I have owned my 05 GT for just over 5 years now. The original owner replaced the battery with a Walmart Eveready 96R a couple years before I bought the car .
I have been thinking about a battery replacement for the last couple years. A few days ago it sounded a little sluggish starting.
The car wouldn't start yesterday so I hooked up the charger for an hour or so. It fired right up and then today it was dead...I guess its time for a battery.

I have to say the old Eveready did dam good, the sticker on it said 09/11 so Sept 2011 makes it around 88 months old. It was made by Johnson Controls 590 CCA 700 A
I bought a new Walmart battery Everstart Maxx 96R. 600 CCA 730 AMP. I don't think Johnson Controls makes it any more...hopefully it does as well.

Once I had the old battery out I measured and the tray would have fit the 40R. The 40R was only just over $30 more, but whatever the other 96R did the trick.

 

Nifty info: Most batteries are made by only a very few manufacturers, and then rebranded. That Walmart battery may well have been the exact same as a Motorcraft or Delphi or Bosch or O'Reilly...

So if it's the right battery, then get it, as it's likely the same maker at the end of it, and they're all made *exactly* the same, except a label slapped on.

And get the higher CCA replacement battery. I did that when my last 'stock' CCA battery died. It's a better battery, IMO, starts faster, and hasn't skipped a beat. After all the weird battery/alternator stuff, I figured why not, and so far... *knocks wood*.

For what my ramblin's worth there. Have a good one!

 

There is only a few companies that make batteries Johnson Controls, Exide, the other one I cant remember now...there may be more, but not many
I have read Walmart batteries no good, bla bla bla, but this last one was great. I remember reading on some forum where this guy said he worked for one of the battery makers. He said they made batteries for lots of companies and rattled off a bunch of well known names including Walmart...basically the same batteries with different stickers.

I believe the original Ford 96R was only 500 or 550 CCA, my new Everstart Maxx says 600 CCA for whatever that is worth...I will be happy if I get five years out of it.
The Everstart 96R and 40R have the same width and height, the length are different 96R is 9 inches long and the 40R is 10 1/2 inches long
So I believe in most cases a person could use a 40R, from what I have read some 40R depending on manufacturer may be around 11 inches long
The battery tray has these triangular gussets on both ends and the distance between the gussets is 11 inches. The Walmart would have fit no problem, longer battery may need a slight trim to the gussets.

 

I've had to replace my battery six times since new, three of them 40R's - 2007, 2009, 2010, 2012, 2015, and 2017. Also replaced the alternator in 2012. I wish I had your luck!

 

just grabbed a everstart "plus" 96r wally world special, its 590 CCA/725 CA, for my 07 v6 4.0 will see how it goes. I dont really know what the "plus" adds but thats what it says. there is a max,a plus and a regular model.

 

My Walmart battery is still going strong. I never did have the battery drain issue and never had the corrosion hood peel either.