If you are going to mess with nitrous-pick a bulletproof drivetrain to start with!
Back when I played with modded V6 Capri's, one of our mob ran a 1600cc Capri with twin 40mm dellorto carbies, modified 1 tonner clutch, big cam, big valves and assorted other go fast bits.
He used to go through around 1 x cylinder head gasket per bottle of gas - and a clutch every 3 or 4 bottles.
Surprisingly though - the standard OEM rear axle never gave trouble, even though it was welded solid.
But jeez did it go like the clappers!!

Accelleration from 100km/h to 100mph was quicker than a certain V6 Capri running triple webbers and home brew fuel.

but at least I had the pleasure of towing the 4 pot back home afterwards

stephen