Opinions on LSD's

[Russwhitehouse]

Gents, I would value your opinions. I am looking to fit a LSD to my historic tarmac rally car to be. It is a 1969 2litre 911 and nearing the end of its conversion from track car to rally car.
There seem to be various options. My Indy Porsche specialist who is doing the work swears by ZF units, but they are seemingly impossible to locate these days ( unless you know something I don't) I can't find one online, but plenty of repair kits for them
Drexler Motorsport do a nice unit that can be fine tuned and adjusted in situ, sadly with a price tag to suit.
Kaaz don't seem to make a unit for a car that old, although I may be wrong.
Quaife make a unit which uses helical gears instead of friction plates which looks OK and not too dear, but is it any good?
If you were in my shoes, what would you fit and why?

[Russwhitehouse]

NJH said:

The american Porsche forums tend to swear by these guys;
http://www.guardtransmissionllc.com/products/limit...

It seems pretty common over here though to just rebuild an original ZF unit with new disks and belleville washers selected to suit.

Do Guard have a european distributor or is it a case of buying from the states. Import duty in France is horrific!!