help! need ideas guys!!

[menace121978]

ok i know some one has had to do this already but i'm going to run my wire harness in the groove on the firewall. how can i get the wires and loom to stay up in there??? i've thought about welding little pieces of pipe but obviously i cant start welding on the cab now, i've thought about glueing the loom... not that type of build, i've tried 5/8" hose ran in there... doesn't stay snug, and my latest idea is to wedge little pieces of 1" pipe up there to hold the loom.

here's a few pics. what do you guys think??