KleenHall

you will lose milage, i did on a 5.3 long ago
plus the loss of torque IS noticeable and it sounds like crap

Will2

iTrader: (1)

One more thing,
The Gibson shorties that you have are pretty much identical to stock manifolds as well. I'm not bashing you at all. Just a little FYI.
Back to the subject line though... Like others have stated. The sound WILL get annoying. If you want LOUD, maybe get a cut-out. Otherwise just get a straight thru design muffler. To answer your question, it may or may not effect gas mileage (shouldnt be much either way). Whatever you decide, exhaust or not, I'd suggest a tune!
There is a lot to learn on this forum.

viciousknid

iTrader: (8)

any exhaust shop should be more than willing to cut the stock muffler off and weld an aftermarket muffler on. just go online and buy a Single in Single out muffler and take it to a shop to be welded in. Or cut the stock muffler off and use Band Clamps to hold the new muffler in place.

budhayes3

iTrader: (19)

Would the band clamps allow the muffler to seal properly? The factory exhaust is 2.75, and most aftermarket mufflers come in .5" increments, such as 2.5, 3.0, etc. When I bought my 3" cutout dump pipe and 3" Magnaflow muffler, I was test fitting them using band clamps and couldn't get them to seal and tighten up at all.

viciousknid

iTrader: (8)

very good observation. seals fine as long as both are same size and you have the proper clamp.
Tried finding a 2.5-2.75 clamp but didn't see one. i say just have a shop weld it in place. shouldn't be much.

slpsilverado

iTrader: (1)

Local shops around here will weld these up for less than $50.

BLACKND

iTrader: (5)

My exhaust guy will weld up a new muffler and dump tip for me for $20 bucks, me providing the muffler of course. I would think that would be the way to go.

If nothing else, Dynomax race bullets are what$30-40 bucks?