[HO455]

Just for a bit of context on icing. I drove my 69 GTO with the heat risers blocked off for well over 150k miles and only encountered carburetor icing once. Driving between Pasco WA and Spokane WA in December.

The car had a 160 degree thermostat with two 1/8" holes drilled in it. The hood scoops were removed and I was running a open air cleaner. The outside temperature was well below zero and the engine would only come up to about 140 degrees.

Earlier that day it had snowed and as always for that area the wind was blowing. So the road was about 75% bare with hard packed icy snow spots from drifts. Driving 45 mph the rear wheels would spin when they hit the icy spots. When I lifted the throttle the engine would die from the icing in the carburetor. If I immediately pushed the throttle down the engine would catch and spin the tires until they hit dry pavement. Eventually I got to a place I could pull over and I shoved my coat in front of the radiator and that got the engine to run above 160 and the icing went away.

Long story but, the chances of encountering icing on one of our trucks at normal altitudes are pretty slim. You really have to stack the deck against yourself like I did.