To add to the confusion, I still have the original factory fitted battery that came with the first GT V6 I had. Its rated, 12V, 60Ah, 400A (!). "Alfa Romeo by Exide", with the charge indicator bubble. This has the correct height 175mm. Dimensions = 175x232x166 mm (measuring narrowest wdith, length). The codes are 0396A855, or 77710581-05, or 60677704.
The battery ordered\ supplied, and at incorrect height has CCA=540A, and is 190mm tall (base to terminal top). Dimensions = 190x230x167 mm. Codes are 0729A855, or 71751141.
V6 GT can only take 175mm tall batteries, due to the strap length, but there's a few mm of extra give for the length, breadth.