When it was all said and done I was using 5/16 x 3.5" on the outside and 5/16 x 3 on the inside. Your lengths may be different due to the thickness of your roof.
I originally installed them with no shims and it looked like crapola because of the variations in the t-top from one side to the...
I don't know if its any help but I just installed those same mounts on my t-top and I thru-bolted a 1/4" aluminum plate above and below the t-top using the outrigger bolts. I also had to spend some time fabricating wedges out of starboard so that the outriggers were more or less perfectly...