Whats new About the OLD ???

I read magazines and always was taught Overhead cams engines are better & and more efficient..Then i recently ackowledged that the old OHV setup still exists in some new cars??...why so?? sometimes i see better numbers from the ohv car then the OHCammer...whats wrong there..is the newer really much better as they claim??? and how the heck are they getting the fuel efficieances they are with heavier cars also with more H.P....whats different (or Better )about them, then the older OHV cars? .......anyone have a clue???

I was talking about the LS1 and the new Hemi...how with bigger engines more Horsepower and weight are they gettin that effieicnt Fuel economy...so your saying todays heads will give me more power and fuel efficiancey then my stock 86 best 200 HP heads???