The silver batteries have a much more stable voltage over life, so I would use them and not the alkaline.
The ASA setting calibration shall be ok for all practical purposes with silver.

Just as a curio, the Spotmatics (up to the F) are not sensitive to battery voltage, so no ASA setting change is necessary (but the battery shall be placed in the compartment inverted, since mercury polarity was opposite to silver/alkaline).

Jorge O