318 to 360 swap screwed up big please help!!!

A stock 360 four barrel has 265 HP
add 25-30 for headers
15-20 for manifold
so you shou get 305 to 315 HP, oh yeah you have those heads which will a bit more too. (these are only guesses, power could vary)
I swapped my /6 for a 360 in my Dart Sport, it developes about 325 HP