Because it's hard to find anyone today who does much over 6k. The first 408 I did was 545 HP and was all done at 5400. It was over. And, according to all the internet wizards in 2000 (moparts was all the rage back then) we had the wrong headers, the wrong ignition and too much cam.
Went I sent the dyno sheets to Danny at Cam Motion, he begged me to either put a bigger HR in it, try solids on that roller, or just put a better solid roller in it and turn it 6500. The customer was wedded to the Internet so it never happened.
At this point, 7500 for a small block bracket engine is easy. Yet you won't find many posted on here that do that.
