It works!, took me a little extra time because I tampered with the float angle by bending it downward a little to make it sit a little lower after I lowered the pump pickup inlet as far as it would go in the tank. I forgot I didn't do a perfect job of centering the new wiper which when combined with the little adjustment caused an overshoot at half a tank causing a reading of ~3/4 of a tank at about 6gal.
Be sure to adapt the new wiper, modifying the original did not work well during tests before installing it in the tank.
I also ignored the fact that there was a little more resistance (binding) to the float movement than normal mainly at empty and thought it wouldn't be a problem. It was and required hitting a few bumps in the road to free it from the empty range after adding fuel not to mention it was sticking at "E" instead going a little below it as I had initially adjusted it to do which had I not been watching the trip odometer would have caused me to run out of fuel. Of course I fixed all of that after having to drop the tank again. Now true empty sits just below "E" to encourage me to fill up at empty when there's at least 2gal in the tank.
The tank is empty at about 1/2 a gal and the needle rests below "E" with 1.5 gal and on "E" with about 2.5 gal in the tank
If you decide to attempt this modification, take your time and perfection is an attribute. Keep that in mind and it should work out fine.
I soldered the two wipers together although it wouldn't be a bad idea to remove the portion of the old wiper that isn't needed if you have a backup float just in case you make a mistake.
The two dimple bars on the back side of the wiper mount are what caused the binding, I had to remove them to allow additional space for the increased stack height with the additional wiper.
Here are some pictures of it assembled on the rail.
The DW200 pump is very, very quiet.
In regards to the OE wiper board resistance, it is not important to get a 0 ohms reading at empty as the gauge will read empty at probably as much as 8-10 ohms, another reason is that the closer to 0 ohms the sending unit is the hotter that variable resistance board gets as indicated by the hot spot on the one I took out plus the worn out extras I have. It appears that is why GM switched to a higher resistance range on the later sending units as the heat is what was causing them to fail or malfunction. The board I took out appeared to have melted some of the solder I applied to the 0 ohm end in an effort to get it to read 0 ohms so it got pretty hot.
Hope this helps someone.