As someone else suggested you could buy THESE and get a custom 2-1 part fabricated.
They need the two outside holes slotted a bit to fit the 16v head. (about 15 minutes work with a die grinder with a good carbide bit)
http://www.trademe.co.nz/Browse/Listing ... =139181702
If you win that auction i can also sell you the 20v 2-1 section for $35 which means you would be able to cut the flanges off to make up your custom 2-1 section.