[FWB]

a word of caution, i currently am in the process of removing plastic wire ties and other plastic wire loom devices from my car. this includes the corrugated plastic wire loom.
let me say IT FREAKIN SUCKS> this stuff is very unfriendly with the extra heat made by headers and the lack of room in the engine compartment. be aware of heat rises and that lip you refer to gets rather hot i would use the steel clamps above the headers and loom that can handle the heat. did i mention it sucks to redo this stuff after it has melted into a homoganous mixture of wires and loom.
as for as connectors, there are ones on the market that has solder inside and reacts with heat from a heat gun, they work nice.

fred

P.S. did i mention it sucks to fix later