HPOP 04 should I switch to 05.

Not worth the expense since you would need new branch tubes as well.

The Dieselsite HPOP should give you very nice reliability.

Edit - what ZMann said!

Where did you get the branch tubes and what did they cost?

Every single 04 6.0L had the "round" aluminum HPOP. The late 04's had the update to the wavy oil rails, but still had the round pump. This late 04 update (from the factory) to the wavy oil rails, required their own specific branch tubes, which are different than the 03 (and early 04), but also different from the 05's.

Jack was referring to issues that seem to have arisen with standpipe reliability. This seems to have affected "late 04's and up" equally. The 03's and early 04's just don't have the issues with their standpipes.

I wouldn't buy one.

Here is another GREAT alternative:

For an 05 and up HPOP, there is no reason to buy anything but an OEM one, unless you want some serious horsepower upgrade.

5C4Z-9A543-ERM

Buy it from a dealership - lots of counterfeits out there.