Originally Posted by macx
EQ head info & source, also flow #'s
That PHR build article made it sound like the 180 runner heads
are also basically Vortecs.
It doesn't really say on the Roger's site, so I emailed and asked.
He said on their listing that only the ones described as Vortecs
are Vortec style comb chambers & ports.
He said the other ones are basically a D shaped comb chamber.
I went through this a while back.. The 180s act like Vortec and outflow, but they are not raised port, at least they don't use the tapered port vortec style gasket. They are preferable, cost more, worth it; raises the bottom a little with a 355.(better ex#s)..perfect for moderate street 383.