For the sake of completeness, and, at the risk of adding more confusion:

"1. So there is the answer for full pressure truck motors into an AD without relocating pump to a higher location."

GM used the term "full pressure" for at least three generations of stovebolt engines (37-63).
I like to use "high pressure" to describe the 235/261 engines that have insert bearings, and no 216-style external/internal oil-distributor valve/lines.

All of the 1954 235/261 car and Advance-Design truck engines were high-pressure/full-pressure engines.
The 1953 Corvette engine (and, maybe the 1953 car engine with the Powerglide transmission option) were high-pressure/full-pressure engines.

Those engines had a high-mounted "external" water pump - same location as on low-pressure 216/235 engines.
This same style of engine/block was also used on 1955 first series truck 235/261 engines.
These engines are, therefore, another "answer for full pressure truck motors into an AD without relocating pump to a higher location."

When the truck series changed in 1955 (to 1955 second series Task Force trucks), the block casting changed to have the lower-mounted newer/later "internal" style of water pump.

I think that someone posted info that indicated the truck model/engine changed (to "second series", Task Force Trucks) around April 1955.

Apparently, all 1955 cars had the new lower/later style of water pump, because the car model/style changed for all of the 1955 cars (the new body style).

It would be nice/educational for someone to post photos of both styles of blocks with/without their respective water pumps. I'll see if I can find useful photos of complete engines.