Have a look here http://rover75.bplaced.net/v8.html under 'Performance'
Assuming they use the same box:-
It looks like 0-62 and top speed are not the same as the ZT 260 with the ZT performing slightly better.
Can't find any figures on 'in gear' accellaration but potentially this is where the autobox comes into its own.
I'll see if I can dig some info out or maybe others have it at hand and can post