Best bet is to swap it out for a getrag and receive the benefit of stronger axles. My fav is the 3.92.
If you have no future plans on building the engine up then going with the HHP gears is fine, but if you plan on camming the car and adding sticky tires those factory axles wont last
What your looking for has a small payoff for the cost. You can figure $800-1200 for gears and install and bumping up a little will only get you a little difference. This is definitely a case of go big or go home. 3.55's won't be enough of a step to justify the cost but 3.92's would be. If you don't have a tuner, that would be a better bang for the buck.
With any gear swap, your going to see a decrease in mileage.
They will work, but if I remember right the 3.5 has pretty good gears alreadyOkay so I have the 3.5 v6 charger se the only kits I can find are on the hhp website they have an upgrade kit for the hemi cars with a package deal that upgrades the entire rear end but it says for hemi cars. Does anyone know if the kit would work on the 3.5l v6.