240 Large Clock vs Tach. What Determines?

As an owner of a 240 wagon, but new to Volvos, I am now on the hunt for a sedan to go along with it. I have come across several 5-speed cars and some have the large Tach with small clock and others have just the larger clock. What determines if you get the large Tach over the large clock? I would have thought all manual transmission cars would have come with a Tach, but I am finding that is not always the case, even when comparing same year cars.

I assume the VIN would be the only way to determine if a 5-speed car originally came that way from the factory vs an auto car with a swapped in manual?

Not sure about later 240s but in my experience the pre-86 GL, Turbo and any other higher level usually had the big tach. The DLs came with big clocks. Never owned any later than '85 though.
Dave B

My 82 242DL came with naturally aspirated 2.1L, 4 speed manual with OD and the large clock, no tach.

It has been my observation that DL's generally had clocks, GL's tach's . . . except for Diesels which got the clocks.

The instrument cluster on the 240 manages both.

The tach and clock both have outlets on the rear of the cluster. My 93 automatic had the clock, it's annoying, so I replaced it with the tach.

Also while you're at it, go to the site http://www.240turbo.com/WhiteFaceGauges.html

It's dave barton's white faces, a thousand percent improvement over stock. You can actually read the gauges at night.