7i92

Sounds like you have a couple of ways you might be able to go. Could you get by with moving the spindle analog out over to the other 7i77? If so you might be able to swap out the one 7i77 for a 7i85. It has 5 smart serial ports and 4 encoder inputs. (You might also need to add another smartserial io card to replace the io you lost from the 7i77 you removed.)

Another way would be to replace your 7i92 with a 7i80DB, giving you 2 more DB25 connectors to add a 7i74 in addition to your 7i77s.

Thanks for all the feedback. For now I decided to cut some Inputs and outputs out, that's not critical, e.g. some pilot lights, and buttons that is not critical to the project right now. So only using the following configuration:
7i92 => 7i77x2 => 7i70, 7i71
But for future, I would like to buy the correct configuration, so, would the following be a good option:
7i80DB, 7i77x2, 7i74x1,7i70x2,7i71x1. And then, The firmware, and possibly sample configuration files for this? And if I understand this correctly, I'll be able to expand further I/O on this?
To make sure I understand this right, Hardware configuration can look like this:
7i80DB => 7i77(1) => 7i70(1)
=> 7i77(2) => 7i71(1)
=> 7i74(1) => 8 x 7i70(2-9)
=> 7i74(2) => 8 x 7i71(2-9)
That will give me 12 Encoder inputs, 12 Analog outputs, 496 Digital inputs, 464 Digital outputs. I know there is no machine that will use this many I/O, but, this is the possibility right?
or Hardware configuration can look like this:
7i80DB => 7i77(1) => 7i70(1)
=> 7i74(1) => 8 x 7i70(2-9)
=> 7i74(2) => 8 x 7i70(10-17)
=> 7i74(3) => 8 x 7i71(1-8)
This configuration will give me 6 Encoder inputs, 6 analog outputs, 848 Digital inputs, 400 Digital outputs? I just want to make sure I understand this correctly, and if there is firmware/software on linuxcnc that will support this hardware configuration.
Thanks