The only thing I had to extend was the power to the fusible links. (Land Cruiser Phil, fusible link relocator.) You well need to cut a small bit out of the in side corner of the battery box.
I also went with his battery hold down kit. It's a big heavy battery and I want it to stay in it's place
That battery has the terminals on the wrong sides. I do run there group 31 battery, really like that it has a second set of terminals that I use to power the winch.
You could compare your battery to the spec's they post