Have just done a slight hack of a Coopers Stout kit, and instead of the BE3 they recommend, I used 500g LME and 500g dextrose. Also steeped 200g of Carapils and 100g of oatmeal.
I got an OG reading of 1.066 which I checked a few times. The kits says it should be 1.038 if using the recommended...