the owner of that FB RX7 was a real hardcore gearhead - the diff on that car was already a 4.11:1 american unit (ford) which was sourced from a UAE scrapyard - I already wrote it was tubbed.
it was a bit of fun to burn tires till 120 km/h and slide sideways doing that, but that also makes it more dangerous and awkward. Not enjoyable - it was literally very hard work driving that car.
as I always say - dont treat a car like a kabab roll at a shop where you choose the body (wrap aka naan, paratha, chapati) and then choose the engine (bihari boti, seekh kabab etc) and then tune (sauces)
you can only do that if you are experienced in doing it yourself, otherwise magazine tuning can really get out of hand.