Most I ever saw on a stock motor was right over 500rwhp. Fuel/Amazing tune I guess but the max on most is right around 450
Some great reading here:
http://www.modularfords.com/forums/s...ghlight=static
http://www.modularfords.com/forums/s...ad.php?t=34527
http://www.modularfords.com/forums/s...ead.php?t=9673