val and val. job??? for the head guys

buddy has a dart with a 360 with j heads 915 and flow 250/180@550 with a old val. job 3angle and stock val...now we was talking and asked if i thought if he went to nail head style val. and a 5/7 angle val. job(race) would he pick up cfm and power......i think so because the val. has a better design and the val. job will let it flow more....it should make a little more comp. not enough to worrie about from the dip in the stock val. to the flat val. but the val. job alone should make some diff.....whats your thoughts on this....and how much should it pick up with the val. and the val. job...or why you think it want help...