The torque specs in the service manual for most every fastener I have worked on are so broad that there is absolutely no need to worry about having a super accurate torque wrench.
I think some guys get way to caught up in torquing everything. Yes, it is a good idea - especially if you aren't super comfortable with the project. But, there are basically three reasons to be concerned about torque:
1. Too loose and the thing may rattle apart. Think compensator.
2. It needs to move. Too tight and it might bind up or overheat. Think of a hub nut on a car.
3. Over-tightening may damage the fastener or the system. They don't want you to strip something, break a fastener or pinch out a gasket.
If you have done enough wrenching to recognize the above, you can do almost anything without a torque wrench.
Again, I am not anti torque wrench, but worrying about one being off a ft lb or two is a waste of mental energy.