Towards the front, just before the nose cone, if memory serves me well its (looking from the nose cone) 10 oclock position, and is a good 4 inches in length, its not cast as per the part numbers but stamped into the metal and spread across a couple of webs. (just incase i'm remembering it arse about face it may be at the 4 oclock position)
often full of underseal or road crud due to it being stamped and location......
in the area marked red
OK I'm starting to doubt myself now so to cover all bases it could be any of the four corners around that end of the box :?