How deep does the mortise lock for Product Code: 40-183 goes into the door frame?

Thanks for reaching out to us. The body of the 40-183 goes into the door 1-3/4" deep. However, the important dimension is 7/8" backset for the edge of the door to the hole for the lever handle. I'm not sure if the 40-183 is suitable for your repair, so we'd like to see photos of the handle set and mortise lock to confirm.