What Can i do to increase HP, i'm trying to get close to 400 HP!

How about a cam swap??

http://www.modernhemi.com/forums/showthread.php?t=217

:drive:

Nice gains. If I were doing it, I'd go with the 260. Reason being the torque would really help the big heavy car move off the line. My convertible is a ~3900 lb sled, and I prefer torque over horsepower in it. It doesn't hit 5500+ very often anyway.