The Pishta route works great up to a certain point, and is a great starting point for anyone not looking for lots and lots of horsepower, say, up to 300, or so...
After that, maybe an individual-runner header may flow enough better to make power power easier to come by.
This header was built by my partner at the time, Freddie Nielsen, a 75-year old guy who had never built a header before. He had a few obstacles, such as, he couldn't weld (had a pacemaker,) and so had to adhesive tape the small pieces together, and then take that to a weld shop to have it tack-welded for final fitment. Once satisfied, he took that to a T.I.G. welder for final welds. Then, it was ceramic-coated, inside and out. Turned out OK, I think, for a first effort. Here are some photos: