I've got one of these round pattern, 6 bolt GM NP205s with the long 32 spline input, the TH400 adapter and the shifter for sale.
$600 for the works and I plan to sell this complete. If you know what these go far parted out you will probably agree $600 is decent, I've sold several adapters for $250.
Delivery possible in some areas, including Austin/San Antonio if you aren't in a rush.
If you are out of the area I'm willing to ship this via Forward Air.
If you want a Buick or AMC TH400 to go with this then ask about those (both have 10 spline quadra trac output shafts however, one is rebuilt).