Even among same group size get the highest cold crank amp battery you can. They do vary widely.
Also I put the biggest physical size battery in the tray that I can regardless of "what it calls for". At group 27 that's a pretty big one, and about as big as you can go. But they're getting hard to find.
At least around here. I think a group 65 is a little bigger length and width, bit a little shorter. I've used them but had to modify the hold down slightly for the extra width