real 340 GTS 4 speed Help? no fender tag just VIN

LS23P9BXXXXXX should be the VIN for a 340 GTS. You can't tell if it is a 4 speed from the VIN. 383 cars and convertibles got the torque boxes. The last six digits of the VIN should be stamped on the radiator support between the battery and the rad. It will also be stamped under the weatherstripping on the driver's side of the trunk rail. You will have to crawl into the trunk and look up to see the VIN stamping. Any seats in the car? You may get lucky and find the broadcast sheet in the springs of the back seat. My GTS had multiple owners and multiple interior changes and it still had the sheet in the springs!