Had my heads flowed by Barnett Performance, the intake flowed 375CFM and the exaust was 220CFM both at .700 inch lift.
The intake lost 5 cfm between .700 and .800 lift but the exaust continued to improve

I would like to stay around .700 lift can the exaust be improved to flow more at .700

You'll have plenty of time to sleep when your dead, let's go