Sierra MC7700 in T400

[niteice]

I'm looking into installing a WWAN module into my T400 (6475-8Q5). I could get one of the Lenovo-approved ones, but where's the fun in 5.76Mbps?

So I'm looking at getting a Sierra MC7700 for AT&T LTE support. I'm aware I will need to use a no-1802 program to patch my BIOS to even accept the card, are there any other possible pitfalls?

One thing which looks like a problem would be antennas, it looks like the MC7700 needs 3 antenna connections but the T400 only has 2 for the standard Ericsson and Sierra cards. Maybe I could steal from the WUSB...

Has anyone else tried this combination?