i figured when the tach was pegged on 7k that it was somewhere in that area. Eagle H-Beams, on a balanced rotating assembly+ comp beehive springs can handle it. Granted, I don't sustain that rpm for more than a second. Rev limiter is gone too.

 

yea lots of guys do ecspecially with the gm847 shift at 7k me personally would never set my shift points over 6100rpms... but thats just me.... lol