Thought torque wrenches were just extra junk until I warped a brake rotor bracket. Was tightening it with a plain ratchet and got it way too tight. Had to replace the whole bracket and bolts. Now I use a torque wrench on ANYTHING that has a spec, especially engine parts. Reading those rebuild threads makes total sense now. My cheap fix turned into a hundred dollar lesson real fast.
Man, I gotta be honest, I've built a few motors in my garage and never once used a torque wrench on head bolts. You just get a feel for it after a while, a good snug with a normal wrench then a quarter turn. All this talk makes it sound like the engine will explode if you're off by five foot-pounds. Most factory specs are super conservative anyway. As long as you're careful and follow the right pattern, you'll be fine without dropping cash on a fancy tool.
Skipping torque specs on head bolts? That's asking for trouble! Those specs are there for a reason, to make sure everything seals right and doesn't warp. A full rebuild is a brutal way to learn that lesson, but now you won't forget it.