guys great info so far - can anyone advise me which gear box best fits a au block , no ecu allowed .

You have a few options..
If you want a 5 speed, you can put in any of the EA-EL T5s they have varing ratios from model to model. Or with an AU manual bellhousing You can have an AU T5, or a BA T5, and I think the AU bellhousing will also support a T56, you'll have to double check that tho..

I can get you a list of the BA ratios later.. but not sure on the rest.

It depends what you need.. Do you start from standstill? If so you want a good first gear, if not you want to match the other ratios as best as possible..

Cheers
MaTTe

yes we have rolling starts using 2nd & 3rd gears only .....

I found the E series ratios on another thread thanks to Damo

EA T5

1st: 3.50:1
2nd: 2.14:1
3rd: 1.39:1
4th: 1.00:1
5th: 0.78:1

EB2-EL T5 (6 cyl)

1st: 3.25:1
2nd: 1.99:1
3rd: 1.29:1
4th: 1.00:1
5th: 0.72:1

BA T5
First 3.35:1
Second 1.92:1
Third 1.29:1
Fourth 1.00:1
Fifth 0.72:1
Reverse 3.15:1

BA Turbo T5Z
First 2.95:1
Second 1.94:1
Third 1.34:1
Fourth 1.00:1
Fifth 0.73:1
Reverse 2.76:1


I don't know what the AU ratios are.. but the EA ones look to be the most lively.. although, with the right diff ratio you could use any of these ratios with little difference.. The lesser the K's the longer the box is likely to last..

But in many respects the T5Z is the best pick.. they're a dime a dozen as the turbo boys don't want them, and you don't need first, so it doesn't matter that the ratio has reduced acceleration.. But it has more hardening on second gear than the BA T5 (I6/XR6).. I'd say get one that has low k's, or is cheap enough to afford a rebuild..

Good luck