Headers or not?

[manyo]

Are you just considering adding headers? What exhaust do you have?

I have stock dual exhaust with H pipe

 

[caspianwendell]

I am going with droptop on this one except he left out one important problem with headers vs manifold which is plug access, some headers make changing spark plugs a complete nightmare. I have polished a lot of stock manifolds to get better flow and have always been satisfied with the results. You can mirror polish exhaust ports and manifolds to get a smoother flow, and less carbon build up but you will need a dremel with flex shaft, inspection camera, a lot of grinding and polishing stones, and a hell of a lot of patience. Oh and you can smooth up intake ports as well but DO NOT mirror polish those.

 

[mjlan]

If your exhaust is in good shape I wouldn't worry about adding headers, assuming that you're still basically stock save for a mild cam upgrade.

If your rebuild included a compression bump, intake change an other other engine efficiency upgrades (it is an air pump), then perhaps the long tube headers would help.

I would maybe upgrade to headers and a mandrel- bent 2.5" dual system all at once at a later time...

 

[c9zx]

Please excuse the source but it has some empirical data that should shed some light on the power question. http://www.superchevy.com/how-to/49178-headers-power-increase/?__federated=1

Another test with interesting data regarding primary pipe size, thermal coatings, and collector extensions. http://www.popularhotrodding.com/tech/1310_headers_dyno_test/horsepower_numbers_and_average_power.html

Chuck