ahhh that sucks. melting ftl. i was going to suggest looking at the OTVC looms we lt1ers use, but your valve covers are too nice! you could give these a go:
https://www.made4uproducts.com/cart/...hp?prod=50-156
they seem pretty nice and survive life atop lt1 valve covers. not sure of your wire size though, they offer 7-8mm and 10.5mm