Auto Trans rec for my 5.7 EFI Swap

Hello,
My winter project is swapping a 5.7 Hemi into a 68 notchback Cuda. I am retaining the EFI with an aftermarket tune-able engine harness.
Question
I want an OD auto trans
I do not want to cut up the tunnel
> The Gear Vendor OD is too expensive at $3000
> 700R4 would be easy , I think?
> 4L80E needs a computer, some trouble, need a harness
Is there a Chrysler Trans that I could use with the 5.7 hemi that would fit with out much tunnel hacking ??????

I have done a search in both transission and this forum .
I find info on manual trans conversions but not to much on an Auto OD unit with a EFI Hemi

ANY HELP , POS OR NEG IS APPRECIATED !!!!
I found threads on the 42RH but they are pricey compared to a chevy . The 42RH might be skinnier than a chevy 700R4 ??