Just had a professional conversion done on my '85 240 from automatic to 4spd/OD. Absolutely LOVE it. One thing, it's not done yet. Donor car was a turbo, mine isn't. Therefore mine has the original non-turbo automatic rear end ratio of 3.73 according to the owner's manual giving me higher rpms at speed than I would like (the manual OD has less of an OD ratio than the auto, curiously). The manual non-turbo should have the 3.31 gears. Is there a stamping or tag somewhere on the differential housing that indicates the ratio? If I find a donor car in salvage, how do I tell from the housing what it is? Or can I, other than seeing if it's a non turbo manual? Thanks.