Installed today the following items:

Pentair 355003S 1 HP 2 spd Square Flange Motor for SuperFlo Pump
Pentair 355067 1 HP impeller
Pentair 355617 1 HP diffuser
Replaced seal plate seal, "rotating" seal, seal plat o-ring, quad ring. The seal set came with clear instructions so that helped.

As expected it was pretty straightforward. The not so clear part is the wiring for the two speed motor as the diagram on the side of the motor was not readable.

One of the hot wires goes to connection numbered with 1 and the second hot wire is wired directly to the black wire of the speed switch (240V connection). I just used a wire nut to make the connection to the switch.

The ground wire goes under the green nut. I did bench test it (up side down bucket) and it ran in both speeds before mounting it in the pump housing.

Here some pictures of the install:

Wiring of motor

Seal plate with new seal

Rotating portion of seal

Impeller

Diffuser

Pump housing

Finished result

Running now 22psi

Motor is warm to the touch, so no longer boiling hot as the old one (I measured 225F on the old one).

Priming the system went smooth. Looks like pump has difficulty running at low speed and doesn't look like it will prime itself at that speed. I am not planning to use the low speed.

Home Depot had a 240V mechanical timer on sale ($15.00) so I picked one up and plan to install that later on this week.

Pressure went down to 22psi (Old motor 2HP with matching impeller/diffuser ran 30psi).

Still have to check the sand filter sand level. Pool water is currently crystal clear but FC is still high (>10ppm).

Turned on the heater as the kids are starting to get impatient.

Thanks for all the advice. Will do tomorrow some accurate measurement to see where I am at.

Ernst