With advancement in aftermarket, cylinder head options well designed headers have become more critical. Unfortunately, reliable, published dyno tests are lacking. On my build struggle with choices. Budget dictated a 3rd set of soon to be asphalt assaulted, SuperComps. Would be interested in first hand feedback on Kooks and Stainless Works products.
I can't recall EVER seeing a dyno test just for headers but that could go a long way to illustrating the value of various exhaust modifications and improvements?
Must dyno pulls I've read use the shops "dyno headers". God knows what kind of trash those things are?
When I was looking for SB heads, I came across a comparison test of heads. The problem was that the 9th graders who did it used a cam that was not complimentary to the flow of the heads. So there wasn't much point to the entire thing.
Going from 180 intake flow on iron heads to 300 on aluminum heads showed no improvements in power. It was basically an RV type cam they tested with.
Dummer then dirt.
In the "old days", 427 Cobras came with these Thunderbird cast iron exhaust manifolds.
The thought at the time was that S/C type exhausts were worth something like 100hp.
That might have been the conclusion after drinking a six pack of Piels shorties? I'm not sure? Needless to say, tube headers help quite a bit.
The thing now in the digital age where beer doesn't help the dyno, everything is tunable.
You should consider though that by playing with the header configurations in attempts to maximize power, you need to constantly match cam profiles and inductions.
On EFI cars, guys spend maybe thousands of dollars to get the last 10hp out of the engine.
On a big block Mustang, good luck with that.
Before I went to the Super Comps, I'd try Doug's 180s. Either way you need to remove the power steering.
The Doug's are big tube and cross over behind the oil pan drop. Much more streetable then the Hooker's which are really for the drag strip with wheel stand starts.