I have a 1984 ton w/ 1976 454 for towing the trailer, it has the stock air cleaner with stock intake hose to the grill of the truck,
Question #1 is which is better a larger filter or K & N filter sucking hot air in from under the hood. or keep the stock intake hose hooked up to the grill inlet ?

Also the snorkle on the stock air cleaner has a vacuum actuated flap that blocks the cold air charge and pulls heated air in from over the exhaust manifold. it never seems to open (unless I pull off the vacuum line of course) it is a little chilly here lately (45f) but shouldn't this open up more once the truck is warmed up?

HELP?