What is the reason it wouldn't rev with a hydraulic?

I don't like the idea of running one on a hemi due to pushrod angularity but can't think of any reason you -couldn't- get it to 7k just because it's hydraulic

69 Charger. 438ci Gen2 hemi. Flex fuel. Holley HP efi. 650rwhp @7250 510rwtq @5700