I have a 69 Mach 1 with no engine (original 351W M code) and FMX trans. I have a rebuildable '66 428 from a Galaxie and plan to install it and its C6 trans. The heads are C6AE-R which are roughly equivalent to CJs after exhaust porting and larger valves. I would like to use long tube headers, but am unsure as to where the actual port opening will mate to available header openings because the vertical position of the opening varies from one FE head to another-even though the vertical bolt hole positions are constant. Which head was modeled for the header construct? Does anyone have experience here? Hooker vs Hedman? other brands I don't know of? Using these original heads saves me a bunch of money and will produce all the power I need, so I'd rather not buy other heads. thanks

 

Hedman is best for Classic cars but you might have to get a custom built at the flanges.
There are kits available on Summit/Jegs etc... All you need is a good welder.
You should have posted this in the Classis section, more knowledge there with the old stuff...