Have you thought of going to an automatic trans? A friend put a GM700R4 behind his 8ba in a 50 woodie. Loved it. Used an adapter for engine to trans mounting, and a column
shift. 2004R works well too. However in your pickup a floor shift would be easy, and there are several aftermarket companies (Lokar) that can provide the shift linkage for that trans on the floor.
Here is a link I found with a quick google search:
https://transmissioncenter.net/shop/...tic-fo1000501/
Some discussion on the other site:
https://www.jalopyjournal.com/forum/...athead.223261/