I'm not trying to bust on you, but FOR THE RECORD - the proper way to build a Galil is with a *new and uncut* barrel. That eliminates all of these timing shenanigans that one encounters.
OK. Now that I have that off my chest, let's see about this.
Hand-tight isn't a good way to gauge it. You need to torque it to 150 ft-lbs for the spec'ed assembly. Once you have it there, see where the timing is. Chances are you'll be at the 6 o'clock position, or pretty close.
There are two choices you can make - unscrew it back out to the 12 o'clock position and shim it, or screw it in tighter and shave the shoulder and chamber to reach 12 o'clock.
Only if you back it out, you'll shim it. Shims are going to be home built from washers or something equivalent, unless someone is making shims. However I'm not aware of anything out there. You have a problem, however, if you shim it too far, because excessive shim size is going to cause your barrel to be too far forward in relation to the receiver. Headspace will then be too "deep" since hte bolt lock up will be "loose" and make the chamber longer front-to-back. The solution is to swap bolts for a tighter fitting bolt (with longer lugs), or you'll have a gun that won't headspace.
If you screw it in tighter, you'll be shaving the shoulder to be thinner to let the bolt go in deeper, and then you'll have too short of a chamber.
Most people find that their bolt won't lock up if the short chamber problem affects them only slightly, because the barrel is blocking the bolt's path into battery. The solution? Polish the bolt lugs with a dremel of small file just enough to help it into battery. Ideally, you'll be done at that point!!!
Now, if it is really off, you can trim the chamber end of the barrel, then ream the chamber with a chamber reamer to make the chamber again into the correct size... depending on how much you need to go. Ugly? Yep. I forget now... is a Galil barrel chrome-lined? If so, you'll chew up the chrome lining when you ream it. Which can make it more prone to corrosion and I think the hard chrome lining is "slicker" than steel, so it helps cartridge extraction. I think.
See what I mean about a new barrel? A new barrel really is the easiest unless you don't mind the extra work.
The real question is how is it timed at 150 foot-lbs of torque. It will hopefully only be a little ways off and bolt filing will be the only task you'll need to do.
I hope this helps - I think it is a little vague but hopefully it will push you in the right direction.
Oh if you torque it in the vise, put some sheet metal or something like aluminum plates or even wood in-between the receiver and the vise so you don't mark up the receiver!