They are making TH350 and TH400 tranny's for the 394 over at Ross Racing engines in Ohio. Quality stuff.
Heres a couple of pictures. He's also making aluminum heads.
Pat

 

Looks nice. Another source of an adapter for this swap is Bendtsen’s Transmission Center Inc
http://www.transmissionadapters.com/Olds_install.htm

 

Cool! Here is yet another company that modifies late model transmissions to fit a 394.

http://www.forwhatyouneed.com/tansonp1.html

 

That's Ross Lombardi, right? I gotta say it's the cleanest adapter I've seen for that swap yet. Wonder about tunnel clearance issues? And next, reckon he'll ever do a 200-4R? Starfires esp could benefit from that with their 3.42 gears- best of all worlds, a nice deep 1st to get that big heavy car moving, and OD for a smooth run on the highway.

 

From what I read, don't use the "T" company in California. They take forever to cut up the bell housing and don't offer much help.

The Ross engineering stuff looks solid!