Okay, i'm planning on getting headers for a 4 barreled 350, i have a weland intake manifold, a really mild camshaft (technically it doesn't do much) a 600cfm carb, and thats about it. what kind of performance gains can i expect? and any suggestions on headers?

 

Typical gain is about 10%, depending upon what you had exactly for exhaust before. Headers alone vs. full LG4 exhaust will produce less gain than headers and full 3" exhaust vs. full LG4 exhaust; and you'll get more gain going from LG4 exhaust to headers and full 3" exhaust than going from L69 exhaust to headers & full 3" exhaust.

Heads also matter. Poor heads like 882's will produce less gain with new headers than good heads like Vortecs.

Also, moving to Exhaust forum.

 

okay sorry about placing it in the wrong place. thing is, is that i have a unkown year 350 under the hood. i don't know what kind of headers to get. can u help?

 

The only thing that could possibly affect header choice is the heads. Pull a valve cover, get the casting #. Most likely ordinary 3rd gen headers will work just fine.

305 vs. 350, and most likely what year of 350, doesn't make a lick of difference.

 

okay thanks, it deffinatly helps, ill get the head casting # asap. would the casting number by any chance give me flow specs?