SImple 'ish' wiring question

[mark '87 930]

I am in the process of rewiring the entire truck. I bought a classic rewiring kit with all the 'proper' connections. My question is this:

The connectors that lead to the wires heading underneath the truck and to the rear tail lights (also has a lead for the fuel tank), where on the truck have you placed them (the connection points). I have long enough leads to have the connections on the firewall (even the fuel sender lead is long enough), but then i have to bundle up all this extra wire near the firewall (the extra i mean is the wiring before the conectors to the main harness). The other option is to run the wires straight down the firewall and tuck them in behind the master cylinder, putting the connections about 1' behind the master cylinder, tucked into the frame. If i put the connectors there, how do i protect them from debris and all that junk?

make sense? do you need pictures of what i mean?