Easy to go electronic from mechanical, expensive and impractical adapter is marketed to go the other way. If a mechanical speedometer is important best option is swapping transmission parts to get mechanical speedo drive if at all possible.
The NV 4500 is a good trans. Some problems with 5 gear when abused and behind a diesel.
Otherwise the gap or step from 4th to 5th is a little big, not the best driving when you need to be in between and neither 4th or 5th is just right, or trying to get to 5th without loosing momentum or lugging the engine.
