Exhaust

Which ever header you get ...make sure it has the correct flange or sized small enough to seal up a gasket.
The 318 has less flange below their already smaller port windows.
TTI has a box to check for this..
Doug's has a part number for this...
Hooker has a one size fits all a body header that seals.
Hedman std 340/360 leak...will not seal..AND are why most people use them with 340/360 heads over the hookers...because the ports are as big as the head ports.