Any ideas wish will preform better stock ported manifolds or headers on mild 400 truck engines

 

headers help get heat away from exhust valve which also helps with detonation prevention. Also a tube around 1.625 or 1"5/8 tube for stock heads is a good place to start on headers. If wanting torque a longer tube is a good thing. having a header that is coming straight out for acouple inches is a good thing on getting better flow. headman 89630 is a good place to check into headers for beginners. nice little header and will have to paint or get powder coated to last. stock manifolds and doing some port work is OK but anything you do to help flow is a bonus. engine is a air pump and the more efficient the air pump the better. Sanderson header makes a header also to check into.