I assume you are talking about the kind with a hollow tube that feeds the gauge inside the cab? If so is that better than an electric one? I have a set of Auto-Meter gauges in my cart at Amazon but they are all electrically powered.
I don't think so, it's the one that was on the truck. I took it apart and spec'ed it before reassembling - it was in good shape and did not need any rebuilding. I'll see if it's the HD version but I doubt it.
I don't think there is an oil passage problem anywhere. I ran wires through them all then flushed them during engine bath time to make sure all were flowing.