Quote Originally Posted by dom14 View Post
2.8GU came with 4.6 diff(and some may be 4.3) 4.8 crown wheel and pinion is an after market Italian import, according to the internet. Yes, AFAIK, 2.8GU diff is H233B, which is a straight swap for GQs. I'm not sure the exact amount of lift on mine. I have take a guess and can say it's above 2". You get the engine braking by switching from higher to a lower gear than suitable for particular speed and revs go high as a result, while car slows down. I'm not sure what you meant by engine braking not happening until 2500/3000rpm.
Sounds like he is saying the car runs on going down hill with the 35' rubber compared to the 31'