Changing to a 4.44 does not allow the car to rev higher it still redlines at 9200rpm and staying in vtec is just the same. 4.44 FD's allow the car to rev faster to redline it cuts the gears shorter so insted of hitting 9000 rpm @ APROX 60ish km/h in 1st gear it will be reduced to say about 55km/h and so on.

Mateusz1993 fixing your diff will depend on what is actually broken if it is the diff that is. Do a search in this forum at the top right there is a search bar, there's plenty of topics coving this and you will get quite a good read about what tends to break how much it cost locally etc. etc.