get em tight but be careful not to strip the threads.
on my new engine, i tightened one so hard it started stripping the threads. I was getting it real tight, i was like "yeah these bitches are tight, no leaks here" and then as soon as a say it, whoose, the wrench gives and turns a half turn, you know how it feels when a thread strips. I was like AHH
What ever you do, plan on doing it again after 25 hours of operation. The gaskets & bolts tend to loosen up over time & need to be rechecked after several heat cycles.