G'Day,
Just wondering how to tell the difference between an 800 box and a 550 box when they're sitting in front of me. I might need to put the 800 box in my car, so I need to figure out which is which whitout pulling one apart.
Cheers
Identifying a gearbox.
The only real way to tell is by counting the number of teeth on the crown wheel sorry!
F8B EFI turbo - Three pots and a snail.
There might be an off-chance that the speedo drive on the F8B box is female, and all F5A boxes have a male drive. Some F8B boxes have a male drive too though, so its a bit of pot luck. 
F8B EFI turbo - Three pots and a snail.