Did 1957 FI corvettes come with column mounted tachs, or dash mounted tachs? I have seen both installed on FI cars. Which is correct?

 

BOTH!
The "regular" FI optioned cars (which was MOST of them) had the typical dash mounted tach (6000rpm with a revolution counter) which was driven off of the rear of the generator, regardless of the hyd cam (250hp) or solid cam (283hp) version. These were options RPO 579A, 579B and 579C.
What has been known for MANY years as RPO 579E, was the heavy duty package (translate "race car" pkg) that included HD brakes, suspension, FI with the special ducted air intake (translate "Airbox"), column mounted tach (8000rpm), no radio or heater. With the latest information that has been provided by Ken Kayser in his new book with TONS of documentation, it is now VERY LIKELY that RPO 579E is going to be accepted as RPO 579D (as it probably should have been from the very beginning).
As best as can be determined, by the documentation which has been provided to date, there were 43 of these "Airbox" cars with the column mounted tach. Furthermore, it also APPEARS that possibly a few cars were built with the column mounted tach BEFORE the RPO 579E (or D) option was officially released by Chevrolet. ALL cars, FROM THE FACTORY, with a column mounted tach, got a 908 distributor. This was the ONLY 57 distributor with the fitting for attaching a cable to drive the tach. Thus, if a 57 Corvette came with FI, BUT NOT A COLUMN TACH, then the dash tach was installed and it was driven by the generator.
For those cars with a column tach, THE ORIGINAL PLAN was to fill the tach hole in the dash with a piece of plastic/fiberglass, sand it smooth and paint it (there APPEARS to be one existing survivor). But it was determined the process of filling/finishing the hole was not feasible, so a front/rear emblem was used to cover the hole. Thus, genuine Airbox cars with a column tach also have the center dash tach hole covered with the round Corvette emblem as used on the trunk and front panel.
So, in answer to your question, BOTH a dash or column mount tach was used in 57, but the column tach ONLY came with a (more or less) factory race pkg.

By the way, I have BOTH tachs in my 56. The column tach is driven by a 65 FI distributor.

Tom Parsons