X-Head Flow Numbers - What to do

The key to getting the exh ports to work is grinding out the valve guide flush to the roof like it was never there, along with the obvious valve job, bowl blend, and short side radius profiling. Take this advice with caution as porting that heavy can carry the risk of finding water, but thats how I do my heavily worked ports. I also find tulip shape exh valves to be around 10 cfm or so better than nail head valves. I liked the Mopar Performance exh valves they were about 25* back angle, but can't seem to find them anywhere.