check the one from flaming river first, you might need the replacement couple too. that piece was on a lot of early b-vans, check out the bone yards .p/n 4037651 (still can be bought from chrysler for $268.00 lol
another option is to find a manual steering column and use the shaft and coupler from it. its not as easy a swap as using an adapter, but its really not that hard to swap the shafts in the column and you might could save a few bucks. I have pics on the old site on a post where i showed how i did mine, dunno if they are still there.
I used a piece of 3/4" pipe, and a piece of 3/4" round stock. i don't remember lengths at the moment, but you basically make it so the pipe is half on the column shaft and half on the round stock, with enough round stock to make up the length difference to the coupler. then weld it together and drill 2 holes (for the roll pins).
kinda hard to see in this pic, but i found one.
I milled out a chunk of metal for an adapter. Bolt in the steering whel wher you want it. YOU HAVE TO BOLT IT IN i made the mistake of not bolting it in. The second time I measured and milled a sleeve then welded it in place. it was time consuming and tedius but it worked in the end. I will try and get som pics for you.
DartKnight, no thats not what i'm talking about. You can actually take the shaft out from inside the column of a manual steering car and swap it into the column of a power steering car. The difference between a power steering shaft and a manual steering shaft is around 6 inches or so of length. The manual and power steering boxes also use different splined couplers aswell. If someone had a column laying around to rob parts off of this would be a simple swap and it would save 100 or so dollars.
dartknight, i dunno if this will work but a later model, column shift manual steering shaft might work in your earlier style column if you were to remove the steering wheel lock piece located towards the top of the shaft. I havent done any measuring personally, but i'd be willing to bet that the length of the shaft is same, the only difference would be that the later model column shafts have a provision for a column lock. It might be worth looking into.