For a 99 LS, I have been thinking about getting a Spectra cold air intake, a MagnaFlow catalytic converter, and possibly a Gibson cat-back exhaust system. I think it should be a pretty decent combo myself. What about you guys? What combos seem to work best for you? I really would like something that has a lower rumble, not too loud, but enough to know it is there. Not completely educated enough about all that is out there to make the best informed decision. Please let me know what has or hasn't worked for you and why. Ease of installation would be a major plus (obviously) for me, preferrably no cutting and welding, even though I could if absolutly nessesary. Feed back is greatly appreciated, thanks!

 

Honestly, I ran intake and a muffler for a week and got decent gas mileage, like 16.5. Cold air intake is always worth it, and as for a catback I had a local shop do a 2.5" single in/single out Edelbrock SDT muffler. Sounds great, don't notice it at cruising speeds, but when I get on it I know its there without it being obnoxious. Just browse youtube for "4.3 *insert brand here* exhaust".

 

if you have the means you could build your own cold air intake at any national brand parts store with off the shelf pieces and pick up a muffler of your choice at the above mentioned parts store and put it together in about 3-4 hrs. depending on skill level you have