Looking for an anto od trans for a 66 /6 Valiant

justme said
Thank you everybody !!! guess i'm looking for a 904 now lol

A nice bolt in would be the A999 version of the 904. It's not an overdrive, but it does offer a lockup converter. As far as I know, there was no A999 for the slant 6 so you would still need an adapter.