I am considering a CUCV as a bug out vehicle and a vehicle to drive in the snow.
Why is the top speed only 55 and why is the horse power so low for such a large engine?
In the pickup, it is because the gearing is so low without an overdrive. I have routinely run my 1009 at 70-80 with no problems other than lower fuel mileage.
Because it is normally aspirated and designed for fuel mileage, not power.
I drive roads that are typically 45 and 55 mph but sometimes its a 65. I doubt I would be going that fast in the snow. What will the CUCV do better than an F250 or K30?
Nothing. It is a 1980s Chevy truck, it doesn't have the creature comforts that a more modern vehicle has, it doesn't have the power that a newer vehicle has, and it is a 25ish year old truck so it will have its quirks and problems that all 20+ year old vehicles will have.
How many miles per gallon do they get just out of curiosity?
Mileage is subjective depending on use. I get about 18-20MPG if I am cruising around town at 50-55 or less... I get 15MPG if I am highway driving at 70+. This is in my 1009 Blazer. A 1008 truck will get less because of the gearing.
The base answer to your question is: What do you want the truck for? For putting around in the snow? For a BOV? For daily use? It has its strengths and weaknesses like any other vehicle, but for my use as a different looking, semi-fuel efficient full size SUV with low insurance rates it makes up for its shortcomings to me.
Later,
Joe