Modifying an F20 box

[l1nuxxx]

Hi there. I'm looking to change 5th gear on an F20 box to give me a better top speed. Is there a kit available? I'm also going to fit an LSD and again what would you all recommend?

[alan b]

what you going to change it for? afaik the one off a wr f18 is longer. easy change. just whip off the end cover. no need to split the box.
diff wise if its a road car with a bit of track use a quaife atb would be grand!