Spacers and Level
Brian,
Here's what you want to do - check Drawing 41 and builders manual 8-17
First - level your fuselage - for 0 degrees lonitudinally. (Actually this isn't necessary as long as you make your fuselage level measurement and your HS level measurement the same)
Use a 1/4" spacer on the TOP of the forward HS spar and a 5/16" spacer on the TOP of the aft HS spar. (this is the same as your 1/16" spacer on the aft spar, but it gives you better surfaces to get more precise measurement)
I used simple old 1/4" and 5/16" drill bits for the spar measuring spacers and taped them onto the spars.
Don't forget the F810E spacers (1/8") that go under the forward HS spar and a TEMPORARY 3/16" spacer under the aft HS spar. the F810E spacers will ultimately become part of the forward HS spar attach structure and the 3/16" spacer is to simply raise the aft spar to get it about where it needs to be.
With the fuselage leveled both laterally and longintudinally and your level on teh spacers, then you are adjusting your HS so that the level reads LEVEL. If you have a Smart Level, that is an even better way to go, but hey, level is level and an old bubble level will work just fine.
The manual confirms in 8-17 that you are looking for zero incidence from the centerline of the HS relative to the fuselage longeron. The HS centerline is near impossible to measure using the structures, so that is the reason for the spacers on top of the spars of the HS. This sort of gives you an extended, but parallel point of measurement for the HS centerline (in sideview) so that you can measure relative to the fuselage longeron. both readings should be the same = 0.0
Don't forget to square the HS with your fuselage by using a common centerline point on the fuse and common measuring points on each side of the HS.
Hope this helps.