Problem using Ino build for 8 MHz
Per the Quick start guide, Ino assumes the board is an Arduino Uno unless otherwise specified on the command line:

All examples were done in assumption that you have Arduino Uno and it is available on default port. Now consider you have Arduino Mega 2560 and it is available on port /dev/ttyACM1. We have to specify this for our build steps as command-line switches.
Board model may be set with --board-model or -m switch. Port is set with --serial-port or -p switch. So lets do it:
$ ino build -m mega2560
$ ino upload -m mega2560 -p /dev/ttyACM1
$ ino serial -p /dev/ttyACM1

For the full list of board names refer to ino build --help.

So you might be able to do this by using
$ ino build -m pro328
$ ino upload -m pro328 ...

However I don't know what options Ino includes for boards (presumably it uses the boards file), so using ino build --help should give you the information you need to select a suitable board if pro328 doesn't work.
Once that's done, the frequency setting should be taken care of for you.