Boss Intake?

Depending on the deal, the Cobra Jet flows a lot more then the BOSS but I don't know your current mods AAAAAAANNNNNNNDDDD most importantly your expectations for this mod.

What are your future plans for the car? Staying naturally aspirated, supercharger etc...

If that's all you plan on doing then I'd do a JLT and instead of intake manifold put that money towards a dyno tune for maximum HP.

I noticed a pretty healthy increase in mid to high range RPM horsepower with the Boss intake and tune. And slightly increased mpg. I attribute this to an increased redline and the tune running on the lean side. Definitely more top end.

The Cobra Jet would be better if you are going to do forced induction at some point, which is what Sparta was inferring.

the Boss intake really does improve performance and a tune is required. But again...it depends on your plans for the future.