cheapest way to convert to manual steering?

I think you pretty much covered your options, If you don't want to spring for the adapter, your other option is swap the column to a manual column. 66-76 box will work.

yea your rite actually lol...thanks for the info on box interchangeability! hopefully the one i have will work, have to take a closer look. Does anybody have any more info or experience with the van swap? or a link to a cheaper adapter?