carb problem???

[pimperout]

im running a 350 with a 4 barrel rochester (i dont know all this fancy talk of bbl's and such im kinda new to the whole engine thing) my engine since i bought it alway ran kinda rough and it sounded really mean and ran nicely but my gas milage was absolutly terrible and it didnt seem to have enogh power so i had a friend time it for me, it was about 15 degrees off so we fixed that and it runs real nice now till you step on the gas then it kinda sputters a bit then returns to normal once you let the pedal out about halfway, i just thought it was flooding so i didnt really think much of it till i bought a parts truck that the owner said did not run it just toook a fuel line cleaning and it run quite nicly soon i noticed when i floored it in that truck it made a satisfying roaring sound when the 4 barrel kicked in and my good trucks did not, so i dont know what to do with carbs or anything i would just like to get some pointers on how to adjust fuel/air intakes or various other adjustments to make it run better.