That depends. But the correct answer is 85% of the guys on here are just cruisers and power doesn’t matter to them.
That’s who should be running manifolds.
I’ll say this again. A header that drops right in and bolts up is most likely a header that won’t make much of a power difference.
On Chryslers you are double screwed. If you have power steering it limits what headers you can even get on there.
And then, because we are all getting old and this **** is drying up you can’t even buy a good header any more.
They stopped making them. So now you are down to paying new prices for used headers.
And that’s IF you can find them and IF you don’t have power steering.
As for the Engine Masters test, an engine dyno like that does NOT measure an engine’s ability to RPM.
I’d suggest on a different dyno or in the car at the track, those smashed up headers would get their *** handed to them.