Before I order this, has anyone ever used/installed this alternator?

New Alternator Land Rover Range Rover Defender 3 9 4 0 4 6 120 Amp AMR2938 | eBay

 

I have purchased a couple alternators now, one for my D2, from California Starter & Alternator on ebay, as well as a starter. I price was competitive and all three are still in service not after 3-5 years to date. I cannot say one way of the other about the particular one you listed, but they seem to have a large volume with great feedback percentage so may be just as reliable with free shipping on on the east coast closer to you.

These are the guys I bought mine from, I would trust this one, and their feedback is great.

http://www.ebay.com/itm/NEW-ALTERNAT...6d8372&vxp=mtr

 

I recommend an alt from a local chain store with lifetime warranty, these French alt are crap my .02

 

I have also had good luck with California Starter & Alternator on ebay