I still have the jig. Its basicly the same as whats in the above pic. It bolts through the crank tunnel and is a snug fit into the cast iron thrust bearing guide on the 71b housing.

DD, i just filled the gaps with filler rod when i did mine. The two machined sufaces did meet properly in a few spots.
I could have taken an extra 5mm off in the milling machine then added a plate but then i would have had to weld around it twice. If the gaps where any bigger the plate idea would be tho go.

I measured the housing lengths. Parted them off with a slitting saw on the milling machine. Then machined each surface to get to the final length.

I then cut out small sections in the 71b housing to be able to get the bolts in to hold the box to the engine(the 71b housing covered the bolt holes).
Put it all on the jig, pre heated and welded it. Waited till it was fully cooled before unbolting it from the old block.

If I remember Simon you used one of your 260z boxes?
that means with the 2.9 first gear its the preferred and
most sought after of 71b boxes. Also alloy sandwhich plate
and the earlier design of the 71b boxes.

That would mean strength issue with alloy sandwich plate
is answered as Jmac was saying, will all the abuse the box
has got, the alloy plate early version of 71 series is
strong enough for very strong boosted A series, especially
considering they sit well behind worked L6 engines.

It has a steel center plate.
1st-2.906
2nd-1.902
3rd-1.308
4th-1
5th-.864

FS6R92A only 16kg heavier than a standard 1200 4spd

Heavenly ratios for a A15
1st: 3.630
2nd: 2.200
3rd: 1.543
4th: 1.210
5th: 1.000
6th: 0.767

DD the first gear is not good for an a15
compared to the Z box ratio but the final
gear suits it for highway usage.
3.63 is actually a little worse than a toyota
t50 box which makes you use 2nd to take off.

Simon remember the centre plate painted silver
perhaps confused it. Im now thinking I should
keep the 71b stumpy and use 260z gears.

First gear is too steep for an A15 but not for and SR20DET --how do you figure? Even the mighty 5-liter uses a 3.35 first gear. Steeper the gear, the more acceleration.

If you prefer lower first, just just fit a lower diff. The 6-speed is still closer ratio than the Z box. Lighter too. Smaller too. And since the SR boys need a stronger box, they are relatively available.

Quote:

Was that 6 speed pic Gelnn's DD?
The hydro 63A Belhousing would lend it'self more to such a conversion as it would have a bigger base footprint than the 56 and 60. Although if one had an illusive 63a you'd just rejig a stumpy L series box to take it.

I don't know where the piccy came from ?

S15 box is still better than 63A -- closer ratios, higher first gear, and longer overdrive.

But for these conversions, why not use an A-series automatic bellhousing? Then no 'good' A transmissions are cut up.

Quote:
The box it came from s15 are heavier cars and with the sr need better gearing for take off. Put it into a 1200 then
the first gear is overkill due to the weight.
2.9 is perfect for first with a powerful engine in a 1200.

Quote: yes but geared for a heavy car and first gear is still not decent.

Quote:
71B is lighter usually while C series are heavier but
6 speed is surely a little heavier than the C boxes.

Sorry for any confusion but was comparing 71b 260z box
vs 6 speed ratio box in terms of first gear ratio.
When you have tried the 2.9 first then you will see how
beautiful it is to accelerate away without quickly going
to the second gear. Its just a good setup and when I had
my 260z it just pulled away from traffic with ease with
the L28 just the factory SUS, extractors and higher comp.

Id love a 2.6 first with the rest of complimenting ratios
to suit that first but too expensive for a 60 series.

One thing I did find if any use to anyone out there thinking
of doing a toyota w setup was the "A" auto bell is exactly
same depth as the W series toyota box and I mean right on.
Prob is W series boxes are just as rare now as the T series
and gearing is not suitable in the aftermarket chinese ones.