Go straight to 8 washers (which is the max) before you start moving the L-brackets. That's what I did, and it did the trick.
I don't remember the size, but since I had to take the hitch apart anyway, I did it before I went to the hardware store, so I could take a washer with me to match.
If 8 washers does not work, then you need to raise the L-brackets 1 space. This will likely have your bars angled upward, which would require you to raise the ball to get them level again. Then maybe too much weight distribution, having to back down to 7 washers.
Sort of have to chase your tail until everything is balanced correctly:
-Front wheel well back to stock height
-Trailer level (or close to it)
-Spring bars parallel with trailer frame (so they slide flat on the L-brackets in turns).
You'll get there!
thebrakeman ('70), DW ('71), DD ('99), DD ('01), DD ('05)
2004 Surveyor SV261T (UltraLite Bunkhouse Hybrid)
2006 Mercury Mountaineer V8 AWD Premier
Equal-i-zer WDH (10k), Prodigy Brake Controller