Article by rocketmangb of the XLFORUM ¹⁾

Both filters have a top bypass.
This means that if the filter does bypass, oil runs across the top of the filter.
Unlike the old filters which had a bottom bypass (many still do).
A filter with a bottom bypass will wash the crap out of the media right in to the engine.
Both have synthetic media.
The HD filter uses a leaf spring to keep tension on the internals and keep them in place.
The Napa filter uses a coil spring.

However, the HD filter offers more media material to filter with. ²⁾
And the baseplate has more return holes.

HD Super Premium 5 Napa Gold 7148 - black version Napa Gold 7348 - chrome version 3)	Baseplates and seals left to right: HD Premium 5 - Napa 7148 - Napa 7348 4)	This tubing cutter style tool was used to cut open the filters. 5)

Cutting open the Napa filter. 6)

Baseplate opened out exposing the drainback valve. 7)	Napa 7148 internals. 8)

Cutting open the HD filter 9)

HD filter internals 10)

The HD filter has more filter media. Napa 7148 (L) - HD 63731-99A (R) 11)