We put a four barrel and dual exhaust on my Mom's 64 Barracuda, 273/904/2.94 gears. Definitely perked it up, but it still could barely outrun my friend's 66 Coronet with stock 318 poly - and that's with a significant weight advantage. So, one race between one pair of cars is not be all and end all evidence, but it did make me think a four barrel 273 with two barrel cam had no more peak power than a stock 318 two barrel (maybe less), and the 318 would be stronger everywhere else. So, swapping the stock 273 for a stock 318 (wedge) would be super easy and make it noticeably peppier for daily driving without making it a lumpy-cammed temperamental hot rod.