following some discussion about the strength of the 002 (5 rib) case VS the 091 case on another forum...

http://www.shoptalkforums.net/viewtopic.php?t=124015&sid=7551df47a6b037c5... 

...I wondered what people on here have found. The name of a pretty respected trans builder in the states was bandied about. I'd be very interested to know what people think, coz a few have told me the 091 is the clear winner, but I'm always happy to be corrected.

The 091 box is a good design in stock form
except for the fine tooth gears in third and fourth,

and the selector hub for third and 4th that seem to often break.

Both these things can be upgraded with aftermarket parts.

002 box from 1800 buses, has coarse tooth gears throughout,
and rarely a problem else where,
other than through wear( they ARE 34 years old).

Reverse gear will always need replacing,(as with any late (73 on) bug trans),
and the mainshaft bearing comes loose over time
and pounds into the nose cone.

These issues are common to most bug, 1800, and 2lt boxes with the later mainshaft bearing, and reverse idler gear,

and all are addressed in a correct rebuild.

Converting the 091 to use a bug nose cone and shift system is more work than a 002,
since the gear stack is longer in the 091.

LanD Industries now make an intermediate housing for this conversion,(091)
so it is now less work,
but still more than an 002 deal.(of which the special housings have been available for over 15 years now).

Is the 091 a clear winner?
Depends on your plans with it, and your budget.

My own boxes are a combination of all the good features, with some aftermarket parts that are better than both.

Some friends I have done 002 boxes for,
get a few upgrades from the 091,
and a 0.82 fourth gear for equal (or less) cruise rpm, but with a coarse tooth gear.
Usually this is because the 091 cores are three times the price of an 1800.

who makes the intermediate housings for the 002?

Also this guy:

http://www.thesamba.com/vw/classifieds/detail.php?id=140691 

This one only uses the 113 mainshafts, but it is simple to bore the housing for the 002 bearing.

Bergs also make a kit for 002 and 113 but not sure if it is still available.

All the kits are high quality and work well.
I have used the Berg, LanD and Morris Race Engines one with great results in shift quality.
This trans has the Morris Race engines housing.

http://www.youtube.com/watch?v=q4eA_RdbNWM 

if I ever put a bus trans in another bug, it'll get one of these and a peloquin I reckon. better start saving eh?

Getting back to my original question, you don't see a great difference in the strength of the two cases? it's just that the 091 is a little more popular?