Thanks. Know i saw most headers listed as 270/340/390/420. But NR has a chinese replacement listed as 340/390, i'm guessing Predator, for $10 rather than the 25 for 270. Pops is tired of burning his leg.
Walking around Princess Auto at all the Real Honda and clone big blocks I notice some heads have an exhaust that slants up like a small block and others that point straight out.
The 270 seems to be the one most often points flat out while the larger displacements tend more to have this upward facing flange.
I would like to know what the internal differences are.