Source

I run their 400 block .030 over for 499 ci kit and have had zero issues.
The balance is right on nice and smooth.
That combo is in my Challenger and have driven back and forth to Carlisle from Cleveland no problem and get to the track a couple of times a year or simple TnT stuff.
Just did a comp test after the season and everything still nice and balanced.
I don't rev it to the moon but no issues for "cheap" stuff.
Watch any aluminum rockers with needle bearings though, not sure if still an issue but there where some when I did my build.