I wasn't aware that regular fuel gelled at lower temperatures?
Gas doesn't gell, but the oil still gets thick, making the starter work harder than it should (I know - use synthetic oil). But a heater makes them warm up quicker and cause less wear and tear, and reduces fuel consumption and pollution from the richer mixture on cold starts.
I have had block heaters on all my trucks (yes, I used to drive gassers :icon_wink: ) since I moved up here to Alaska many moons ago.
There's a couple of options:
A freeze plug type heater that requires you to drain the coolant and replace a freeze plug with the heater element. They can be hard to install if you can't find an easily accessible freeze plug.
Tank type heaters that you mount down by the frame and run hoses from a block drain port to the heater and then up to a tee in the heater hose. They heat the block by thermal circulation (hot coolant rises to the top, and cold coolant enters the bottom of the heater). They are generally easier to install than freeze plug heaters.
Another is a glue-on oil pan heater - they heat the oil, but are less effective in heating the block.