Safe RPM for a 408" Magnum?

The hypers should list a piston speed limit, or there should be some online info on that, I believe your cast lower end will survive with good rod bolts. I pulled the bottom out of a stock 340 piston at 6400 RPM just revving it. Yeah, stupid move on my part. I was showing a potential buyer the motor at the time! #-o

I would think a stroker would be cammed for torque more than top end.