Cooler intake manifold

You didn't say which intake you are using- if it's an Air Gap type or clone, it already has the exhaust crossover eliminated, and the runners and plenum isolated from the valley, making the valley baffle redundant. On a stock, LD340, Stealth or Performer style manifold the valley pan is a good idea, the crossover may or may not be present on the aftermarket manifolds, but would be a good idea on a factory one.
Cold air kits are great, lots of versions out there. What I like to do (I'm all about low cost) is use the air cleaner and ductwork from many ('89 ish?, and up) TBI and Magnum Dakotas, Rams, and vans. Takes a standard element and bolts right on to a 4bbl carb. The different applications use different length ducting, so measure and select the one you can make work in your application- or make your own with metal dryer vent hose. I'd be surprised if the whole thing cost you more than 10 or 15 bucks at the pick 'n pull. I've even cut and welded 2 housings together to make a dual-hose setup if you have the room.
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As far as carb spacers go, yes, the hardwood or phenolic spacers are the way to go; but if hood clearance is an issue, or tuning dictates a small or no spacer; consider a heat shield instead. Still reasonably effective, and not overly expensive. They're not tough to make yourself, either.
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