Wow. Someone got offended.
I build my own engines, and I have a stroker small block that has seen well over 600hp when it gets a 150 shot of spray, and it made over 50 passes in a 4800lb 4x4 truck, and is still happily alive in my Dart right now.
The Dart (which also has a 904) gets driven on the street frequently, and for some reason, the engine doesn't explode every time I crank it up.
The problem I have with what you said is that if you're telling customers that a small block won't handle over 600hp, then they immediately take that as gospel, and start spreading bullshit rumors.
Then those rumors turn into a general statement like "Mopar Small blocks are garbage, and can't handle any power." Which is complete bullshit, and anyone who has ever actually built one knows that.