> in cold weather, since it will likely need carb heat.
Dunno what you call "cold". When below freezing you don't need heat. You DO need heat when 38 degrees and misty rain.
You probably know this from aircraft but the symptoms are different on the ground. It's just above freezing, and a lot of fine water-mist. Engine idling or 20MPH, throttle near closed. As the air comes past the throttle plate it expands. And cools. Several degrees. After a few minutes the throttle is cooled. To freezing. Ice builds on the throttle plate and adjacent walls. Engine sucks, air cools more. (Evaporating fuel plays a part also.)
My Willys always stalled at the end of the block. If I restarted and gunned to the end of the next block, it stalled again. If I left it stalled for a couple minutes, by now there was enough heat in the manifold to warm the throttle area back above freezing. OK until the next cool damp morning.
So: no heat to start. There's no heat available, your choke gets you started. Run at damp 38 degrees, ice forms. 5 minutes out the manifold heat does the job. But in the 2 minute to 5 minute interval it will NOT run slow without icing up. That's what the wretched flex to the exhaust stove is for. (It may improve economy in the 40deg-50deg zone, but obviously you do not care.)
No trouble when air is below freezing, because there's little or no loose water in the air to ice-up.
Aircraft can get in trouble at much larger throttle and fully-warm because of more extreme air conditions and typically less manifold heat. And while I could let my Willys stand for a few minutes and thaw-out, an airplane at altitude usually can't.
> Might use an open type in summer.
Experience with a couple ~~1979 GMs says you may need snout air in summer. A Chevy Six and an Olds 350 would ping like a bucket of marbles unless the snout hose was sealed all the way to grille air. Any underhood air getting in, you thought you got a load of 69 octane gas, but fixing-up the snout and duct cleared it up.
So don't fix that hood too much. Whack a big hole and use a Shaker intake.