Helical LSD Alternatives?

[guitaraholic]

For those of us who like "grip" driving I have been told nothing beats a helical/torsen LSD. As of right now it looks like we have three choices, both with there pro's and cons.

OBX

Pro's
- Cheap
- Uses Open Diff Shafts

Con's
- Lack of quality controll/craftsmenship
- Must be shimmed
- MADE IN CHINA (that's personal, but I hate
supporting a country that is going to one day
try to take over the world)

Quaife

Pro's
- Awesome Craftsmanship
- Lifetime Warrenty (even if raced)
- Good customer service/support

Con's
- Very Expensive ($1350 or so)

S15 HLSD

Pro's
- OEM Quality
- Lower cost than Quaife, but still expensive

Con's
- Need to buy output shafts (adds to cost)

OK, that being said I've been reading up on other vehicles that use Helical type LSD. Some can be had for as little as $450 new. They are OEM quality and some of them (like the one for the Firebird) can handle tons of torque. So here comes the question........

What type of custome work would be required to get something not of the same manufacture to fit. I am speculating, that it might require custom fiting of the differential case, and output shafts. This is just an idea I am throwing out there. heck, if its something as simple as drilling a few extra holes for the casing, and come custom output shaft (or machining of some) it might be a cost effective alternative that is OEM quality without spending a grand or more