I'm gunna base my response off of ratio411 because it sounds like he's done the research I'm to lazy to do but If it has a better "breathing" grind than the E303. DEFINITELY go with it. Don't mind JordanB21 though.. Not everyone has money for a whole top end upgrade.. I can't stand asking question or reading forums looking for answers to see "That One Guy" always saying what you should do rather than answer the question at hand. Plus with stock 289 heads w/ work + 11:1 compression, Dual plane intake + 650 dp Holley and stage 1 comp cam. Launches are pretty violent... But yes; Heads and intake would do some work to the power, They are also not a necessity.