Tetrylone

Hi all. I recently go an 88 jeep xj and the previous owner said he fabbed a closed cooling system for the xj. He had briefed me on the fact that if, after draining the system, you didn't start it back up correctly that it would vapor lock. I can't reach him now and I'm trying to figure out what it is I need to do to keep this from happening.

Gonna throw a new motor in the xj and I wanna make sure it goes well... sure don't want to vapor lock a new motor. Any one have experience with this? What can i do to ensure it doesn't vapor lock after i drain and refill?

Thanks!

Oh yeah- He said something about the expansion bottle always bursting so he replaced it with a stainless steel tank. Not sure if that detail helps at all.