Just a final word, have worked out a which other codes are compatible- hopefully might be useful for anyone else looking for a gearbox. 6G, 8A, 4Y and ACN code gearboxes have the same final drive, same 90mm flange size and virtually identical ratios. Codes ACL, ASF, ATH and AON will fit if you change the CV flanges to 90mm. I don't know for sure about the ATH box, some sources say it has a 24mm input shaft size, some say it has 22mm.