Even with the 90 adapter I don't think the OE speedo cable will reach, as mine was about 6 inches short and I had to get an 80 inch cable.
Hard to tell from the pics, but that may very well be the 46RH, and I can see the plug, but not enough to tell the number of pins. (3 pins is an RH lockup)
That also may very well be a diesel trans due to the 6 lugs on the converter.
All it takes to use a diesel trans is to change the governor for a gas one, and they are heavy duty as well but the converter wont fit the standard gas engine flex plate.
More trees.:D
The 42RH barely fits in the tunnel with no floor mods, but the bigger ones need more real estate.