340 HP's vs headers

Didn't read through the thread. IF your 318 manifolds are the 1 5/8, you'd gain by going either 340 manifolds or headers. Even the later 340 manifolds are 1 7/8. Pro's/Con's, I'm sure would be listed in everybody else's post
I am back on the 408 stroker deal. I posted the temp use 318 deal on a different thread.