Switching from eth to ser-1 (T1) for external interface

[Snowbird]

I have a router in between my new IP350 and my ISP
that I want to get rid of by plugging our T1 line
directly into the IP350 T1 card.
(The previous firewall did not have a T1 interface)

My ISP uses small /30 interface blocks between their
router and our network, and then routes another block
of addresses for us to use for our public IP block.
The small /30 interface block is the standard they use
for all customer interfaces.

65.18.96.28/30 - ISP interface block
65.18.93.3/29 - LAN block for our public IP's
10.50.0.0/16 - internal network

Currently my setup is:

65.18.96.28 - ISP gateway
65.18.96.29 - Outside of router
65.18.93.2 - Inside of router
65.18.93.3 - Outside of IP350 (eth4)
10.50.0.0/16 - Inside of IP350 (eth1)

And I want to remove the router and go to:

65.18.96.28 - ISP gateway
65.18.96.29 - T1 interface of IP350
65.18.93.1/29 - (eth4) Public Lan block but nothing plugged in
Needs to be routed out via T1 interface
(Do I even need this interface anymore?)
10.50.0.0/16 - (eth1) Inside of IP350


All my NATs are setup using my pubic IPs and working now.
I don't think those would need to change...

Right now my default gateway in Voyager is set to 65.18.93.2
Do I need to change this to 65.18.96.28 after the switch?

Also, how should I change the gateway topology in
SmartDashboard? Delete eth4 and add ser-1(T1) as my
external?

Screen shot of current Voyager config is attached.