I'll jump in here because I was one of those who commented about leaky headers.
My '63 C10 (283/327/400) started off with Ram Horns, but I was a teenager who wanted "More Power" so I added headers. I could only afford the cheap ones at the time, so I got what I paid for. I was always having to replace manifold gaskets, no matter how many times I tightened them. Same thing on my '77 Blazer (350). Again, cheap headers.
I also had the collector flange go bad on a couple of sets, so I welded those to the pipes to solve that problem.
I will agree that it was probably more of a quality problem than a header problem.
Fast forward to my current '62 C10. I have a '67, 275 hp, 327 V8. I am not trying to find all the horsepower at wide open throttle, but more trying to get a decent amount of torque in a usable power band and at a decent rpm range. Enter the factory Ram Horns. Good design and solid performance/reliability.
To me, it is more about daily driver reliability that I would not be afraid to send my wife or daughter out in the rain in that truck and not worry that they will have trouble with it, than it is about max horsepower.
Both my '63 C10 and '77 Blazer had headers and glass packs. The loud roar was what I wanted. Not so today. Now it is Ram Horns and Magnaflow mufflers. Still a decent rumble, but a lot more refined.
