lost headlights and tail lights

[Wildstreak]

Edit- Figured it out was the alt wire, delete post

[dmjlambert]

Well the fusible link is responsible for protecting all your unfused wiring in your truck and for reducing likelihood of an electric fire, so I recommend don't bypass it even for 5 minutes, replace it first.
Sometimes an item that is missed during an engine swap is forgot to add ground wires between engine and frame and body. And pinched wires can be a problem.
Your headlight switch has a circuit breaker in it, perhaps it is tripped due to a short, and perhaps that short also melted your fusible link.