If you still have the adapter, would you be willing to part with it for a little while. I've been wanting to make one for myself and it would be a hell of alot easier if I had one to copy.
just redrill the 203 for the round 6 adaptor and use the 4wd tail shaft.
i used a 4l80e to 241 adaptor with my setup. was fairly easy.
if you were a paid member there is a full write up with lots and lots of pics in our tech writeup section i did.
and in the garage section we have a huge thread on 4l80 to 205 info with lots of tech info and pics.
shows full reman of 203 range box and 205 and ord tripple stick shifter with adaptor.
that 4l80-e to 205 adaptor is worth a lot by its self.