Realistically I don't think there is any hydraulic roller currently available that will take a side oiler to 6,500. Last I heard the limit with the BEST stuff was around 6,100 or so on a good day. My side oiler is not stroked, by the way, and has seen 7,000 rpm on a number of occasions.
A recent Shelby build I was reading about, Shelby block, E-brock heads, hydraulic roller, a typical "modern" FE build for today, cranked out just UNDER 500 horse at 5,600 rpm. Yawn,,,,
BUT, it did have some remarkable torque from a relatively low rpm range, so that's pretty cool.