300TDT speedo - mechanical or elec?

[BWBody]

Mea culpa... didn't realize I couldn't tow my '83 300TDT wagon on a dolly with the tranny in neutral. Blew out the trans.

Planning to replace transmission. Would like to buy a take-out trans in advance before going into shop. Is there any easy way to tell if the speedo is electric or mechanical drive? Even the dealer couldn't tell me by VIN due to vehicle's age.

Located a replacement electronic drive trans through Potomac, but it won't help if speedo's mechanical.