I read on another forum about a 200R4 swap from a Powerglide transmission.
It is a direct swap, but you would need a trans crossmember for a TH400 & it bolts right up w/out having to change the driveshaft.
MBHD
I've read that you can re-use the crossmember. You may need to drill new mounting holes but you don't need to spend money on a new crossmember. Some cars have the holes already there. I suspect that's the case for our Camaros.
I'm all for saving a buck as long as it's not sacrificing safety or quality.