if it is stuck in the heat off position, you could probably not even worry about it, Mine had the spring broken off for probably 20 years, I actually had no idea what it was or what it did, the truck just started and ran so well, I never looked for a problem. Even at 20 below zero, it ran like a champ. The little flapper is hardly a tight seal, and the two parts are bolted together so closely heat transfer is quite good anyway. But if it is in the heat ON position, then you will have trouble. But yes if you feel you really need it to work, Just be patient, you will need patience if you are going to work on these trucks anyway.
Hey Broke, hear me out.
I ran a '52 with a flapper stuck in the closed position for 20,000 miles without drivability issues. The climate in Virginia Beach, VA is entirely different than Connecticut, but it does get cold enough to warrant having this thing functional.
Even though it ran fine upon startup and throughout the warmup period during cold weather, I am certain that a lot of non-atomized fuel got dumped into the cylinders, washed the oil film off of the cylinder walls and contaminated the oil with gas. Atomized fuel hits the cold intake runner and instantly becomes liquid fuel which does not burn.
That is exactly why GM spent all that extra money designing and manufacturing that intake heating apparatus.
The lack of a functioning heat flapper will reduce the life of an engine. It isn't something which you would notice on a daily basis, but it is happening just the same.
Carl
