big block/small block

new to the forum and would like to find out the best avenue to go.. i just purchased a 74 dart swinger with a 318... body is in great shape with 74000 original miles.. i do want to pull the 318 and drop more HP in it.. what would you guys recommend? i am poor boyin of course... i am undecided on whether to go 360 or big block.. which would be more bang for the buck?? i plan on using a 727 with 83/4 geared at 4.33 or 4.56... it will be a daily driver,, but dont want to be late for work... any ideas/ suggestions is appreciated