I think the guy was talking out is backside I'm afraid mate. As already stated in earlier posts you'll need a new managment system, low comp pistons etc, etc, etc. Your re mapped ecu will be mapped to your currnet fueling, cams etc so thats going to be usless. Even if you only do as Ryan says, you've already blown over 1k. Then you'll need it R R'd to get it set up. Bear in mind my mate just sold a FULL G60 setup for less than 1k.
Seriously mate, unless you got a few grand laying around, stick the eaton back on ebay & if you just want a bolt on mod go for Nitrous Oxide, 50-75bhp extra out the box.