you wondering what u need to make that a 5spd L52 HD?
inner bearing carriers must be bored out to the proper spec, Marlin ships to Australia all the time, just call or pm CJ http://board.marlincrawler.com/index.php?action=pm;sa=send;u=2030
Yeh seen a bit of info on pirate 4x4 about building up the HD version but need a bit more info on actually doing the rebuild
Machine work on the box itself is not a problem can get a mates old man to this in his engineering shop (always working on this sort of different projects)
