30-03-2018, 09:05 PM
When you read a handbook for larger austin of the period, 12/4 for example, they all have what are referred to as decompression taps fitted to these holes, they were used to find compression stroke when setting timing etc. Quite why the factory continued with the expense of fitting them for so long is a mystery to me, one could remove a plug to effect the same thing.
Black Art Enthusiast