[blykins]

Where would you like the powerband to be?

The 284 cam would be more suitable for a Cobra...and would put the peak hp at around 5500. You would still have a very streetable engine, with good low to mid range power.

The 274 would be more suited for a lower-rpm application where you need more bottom end grunt..i.e. a heavier car with higher rearend ratios, or a pickup truck.

Keep in mind that Comp Cams' catalog is oriented so that the comments apply to the smallest engine in that particular family. In your case, the notes are for the 429 engine. An engine with 460+ cubic inches needs a larger cam because it has more cylinder volume to work with.