Yes they will. For direct hp you'll have to search for.
Installing an aluminum intake can potentially increase horsepower by optimizing air flow into the engine, but the effect will vary depending on the specific vehicle and its engine characteristics. Other modifications and tuning may be necessary to fully capitalize on the potential horsepower gains from an aluminum intake.
cold air intake
Upgrade the intake, exhaust, and fuel injectors.
it varies on the manifold and engine. if it helps move air it will increase horse power, if it doesnt, torque.
Cold air intake, supercharger and down pipes.
Air does not come out of an intake mainfold, because the intake manifolds are under a vacuum. Now exhaust manifolds, that a different story.
On a V8 engine there is ( 1 intake manifold and 2 exhaust manifolds )
Most popular intake manifolds are Edelbrock, Weiand, and then there are performance manifolds from Ford, GM, and Mopar. Hope this helps -don't know much about that ricey cone filter CAI crap...
cold air intake, K & N airfilter dual exhaust
Aftermarket retailers such as Summit and Jeg's have a variety of manifolds for this application.
To increase the horsepower of a diesel engine you need to put either a turbo charger or a supercharger on it. Cold air intake will also help.
add an air intake and full exhaust system if you havent yet done that