so i just finished fitting the 323GTR seats in my BA V6 and it made a good difference (atleast for my narrow behind :P )
pretty straight forward really,original brackets fit and seats are the same With.
what needed to be done : drill New holes on the backend slide to fit the seat.
and note : Driver seat needed to be spaced up at the door side about 35mm or otherwise it
would be crocked (think this is because the seat is sligtly lower on one side because of the 4x4 tunnel,havent really gotten to measure it)

so if you want to sit tighter and abit higher up,this is recomended ! i do however not recomend this to People taller then 180cm,cause Your knees will probably argue With the steeringwheel