Hemi to Cast Crank 440 Converter Question

Currently have a Cuda with a '69 Hemi and a 727. I am going to be pulling the Hemi out and dropping in a '77ish cast crank 440.
The question I have is in regards to reusing the torque converter and flexplate.
I am thinking that I need to get a B&M flexplate in order to use the existing converter.
If I need the B&M, which one do I need since they list multiple big block plates?

10238 - External Engine Balance, 2-Piece Rear Main Seal, SFI 29.1, 6-Bolt, Chrysler, 440, 727

10237 - External Engine Balance, 2-Piece Rear Main Seal, SFI 29.1, 6-Bolt, Chrysler, B/RB, 727

Thanks
Greg

I cant think of a reason why they list 2. No 440 had a specific flexplate. Maybe the converter bolt holes are diff diameters for diff size converters.

One should be for a cast crank motor the other for a 440+6. Call and ask. Dave

you want the 10237 it has a big pac man bite out of it to balance the cast crank
http://www.summitracing.com/parts/BMM-10237/