I had a good experience with the 305 in an 1984 K5 Blazer that I used for plowing snow in far NE Minnesota.
I used it from 1984 to 1993 as my recreational and work vehicle, added the plow for my own road, then picked up other jobs to keep me in some extra cash all winter. I switched out the clutch fan for a direct drive fan for cooling, and switched out the automatic hubs for manual lockers.
In addition to it being my weekend hunting/fishing rig, involving light towing, I ran about 14 plow jobs with it through some really tough winters, including 1995/1996, with over 150" of snowfall at our house, and record cold down to -45f actual air temperature (the same night Tower set the MN record of -60f Feb 2 1996).
That year in particular I can't count how many times I was either stuck due to snow falling down off the banks back into the road and piling up to stop the truck. I shoveled what seemed like over 100 tons of snow from in front of that straight plow blade. There were a lot of narrow roads on my route so I had to subcontract late winter with my neighbor to bring in a bobcat to push the snow back between the trees to make room for all the snow, which never melted much at all that winter until well into April, with snow piles in the shaded woods until after Memorial day.
Anyways that truck never used much oil, ran smooth, never made any bad engine noise, never left me stranded, always started in on the coldest mornings after sitting outside all night, and was just powerful enough to get the job done, but not so powerful that I was able to damage the front end or drivetrain.
I sold it with over 150,000 hard miles. The truck did not have a straight piece of metal on it, but the old 305 was still running strong. To this day I like it better than the 5.3 in my Suburban which consumes oil, smokes on start up, and has a piston slap on cold start up.
