There's two ways to do it:
Take a stock front block, and put an adapter in the 1/8th NPT port in the bottom of the block. The adapter is a bell shaped part with a tank thread female bottom, and a male 1/8th NPT top.
The other option has the ASA built into the front block. There is no adapter, the ASA is just an extension of the front block.
Here's some examples:
The far left block is a standard block with an adapter.
The second to the left has a integrated ASA