http://www.find-a-part.com

I got an XR2i engine to go in my Escort Cabby from here - came with 3 month warranty etc. as well and was mine for £140 delivered with pretty much everything so I ended up with alot of spares

You send your request in and scrap merchants and shops etc. call you back if they have the bit you need in stock!

Cheers,

Andy