l wanna convert my 2005 Impala SS from an automatic to stick shift. How much time and money would it take on average to convert a car. Also does it add any horsepower once its been converted.

You need to remove ur transmittion first, then u need to get yourself a manual transmittion. A good one should cost u about $2500. l recomend a 6-speed, u can probabily get one out of a wrecked F body(Camaro, Trans AM). Maybe u can get it for about $1000-1500. Then, u have to drill a hole in ur floor board for the clutch, & the shifter. You have to install the new transmittion(if it will fit) & install the cables, stick, clutch.. so on & so forth.
On average, with labor & parts. l would say it will cost u about $3000-$4000 depending on the quality u r going for.
and yes, & manual transmittion will give u a little more power, & more torque as well. Not to mention, u can dump the cluth now & then to light the tires up!
good luck

First forget dkwr is answer. Your Impala is front wheel drive & cannot use any transmission from an F body car. l do not think there is any 5 or 6 speed available for it, only the factory 4 speed. And that will be expensive -- very expensive.

We old hot rodders call ur car wrong wheel drive. If u really want to spend time & money on a hot Chevy get a car with front engine & rear wheel drive. Not that the Impala is a bad car, but it is just not hot rod material.

A manual transmission probably wo not improve the performance on the Impala enough to notice -- certainly not enough to justify the cost. And u have to remember that fwd cars can have tremendous torque steer problems, so increased power usually just means increased trouble when u try to lay that power down through the front wheels.

Sorry to be the bearer of this bad news. Get yourself a 90s vintage Camaro or Firebird & do some real hot rodding with a V8 up front & drive in the rear where it belongs.

The first response is out in left field, here is a tip.if you do not know what you're talking about do not respond. The poor guy would be looking to put a completely incorrect transmission(notice the correct spelling lol) in his car.

Ben is right. l do not know if there is a 5 speed FWD trans that would bolt up to that motor. You could try one of the Grand Prix boards, if anyone has converted to a manual it'd be one of the GTP guys.