Are flower masters killers of hp?
 

I 'read' that flowmaster 44's are hp killers is this true i have lt's too
what is the best hp muffler
want a nice 212/218 comp this summer

If you like the sound just put a cutout in front so you can have free flow when you want.

Chambered exhaust don't flow super well. Get something with a straight thru flow.

for a stock setup, a flowmaster is fine. the chambered mufflers sound the best of all of the designs in my opinion. once you start getting into some of the larger mods, the chambered mufflers are more restrictive than a straight through design. some engines like a bit of back pressure, but the LS platform loves to breathe. any straight through design will basically perform the same power wise.

if and when i get a cam would i need that cut out or less restrictive muffler?

Cut out to me is not worth the hassle. A nice big magnaflow sounds awesome and gives you all the flow necessary.

i have a procharged 53, it has 1.75 headers no cats with a 4" exhaust. i run a flowmaster 50 series and a dynomax ultraflow in combination....very nice sound. the flowmaster really helped alot to tame the sound and make it tolerable on long road trips.

make over 500 hp with no issues

I run a Spintech muffler (chambered) on an otherwise stock exhaust system. sounds great!

With the mods that you want to do I would focus more on what sound you like best. To me cutouts don't sound good and will cost you more money. If you decide to add a turbo or a supercharger than I would recommend getting a straight through design to maximize your application.

Big power yes, every day driving.. no Unless your drag racing or all about top hp, FM is fine..