Hi everyone,

Im running a stock A15 4 speed original diff i think (H165)I had the A15 4 speed conversion done in adelaide and drove my car from adelaide to brissy and it drove fine until i got to brissy the box went a week after i got back.

I had plans to find a five speed as it would be handy for all the long highway trips i do but ive learnt 5 speeds are rare and expensive. Would a higher ratio diff be the way to go in the sense it wouldnt give the gear box such a hard time at higher speeds.

If any of this makes sense all feedback is greatly appreciated thanks