Question on traffic sourced from a multiple interface LTM

Just the manual: http://support.f5.com/kb/en-us/products/big-ip_ltm/manuals/product/ltm-concepts-11-4-0/2.html?sr=32543245

Basically just create a pool, put the 10.50.50.1 address in it with port 0. Don't worry about monitoring it, just leave it unknown. Or ping it if you really must have it green :-)

Create a virtual server, select Performance L4 instead of Standard, network type instead of host, destination address 0.0.0.0 mask 0.0.0.0 port 0, select All Protocols instead of TCP. Instead of All VLAN's make it enabled only on the VLAN where the 10.27.27.x servers live (the ingress VLAN for your outbound traffic from 10.27.27.x). Point it to the pool you just created with the firewall address in it.

Now any traffic initiated from that VLAN will be processed by that virtual server rather than the routing table on the box.