A mate had an 02 GTO 5spd stuck gt28r's on there with fuel pump upgrade and intercooler and rad with a remap it made about 370 @flywheel at low boost.
Awsome little cars you just need to keep your eye on them all the time.
He had engine mounts replaced and a new complte exhaust system it was an animal waiting to be unleashed even more.
weighs roughly 1250kilos from memory.
New Ohlins suspension.
Modified rear clam and lights. Much better than standard imo and 'usa' style (big in usa too)
The noise was something else with v6 twin turbo through the exhaust.

The gearbox gave up on a hard launch in the end but it was torquey at 12psi.