my thought on this is.... Call owner. Ask for full vin number on dash board.
If it is a 340 car or dash for that matter it will be VS29H2 and then the number of the car. If it has a fender tag ask owner to read it to you and write it down as he reads the numbers to you left to right bottom to top. post the info back on your thread and someone will get the info for you. I am going to assume you know where to tell the owner to find the above info...