Tips
 

will 18 inch long chrome tips change the sound at all when i put them on. they are 2 1/4 in and 3 1/2 out.

It should make it louder. Think of it like a megaphone, little on one end and big on the other, they amplify the sound.

There will be a volume of air inside the horn that will now be compressed by the exhaust flow, this will cause a reverberant "beat" at different RPMS.

From behind the tips, the sound will be louder, and with a directional quality.

If the reverb gets to you, just learn what RPMs minimize it.

Why do you want these on your car anyway? Or are they for looks alone......

Just for looks i was just wondering if its gonna get louder

The more pipe you put on your exhaust, the quieter it will be. My cat back exhaust splits apart between the muffler and the tip just over the axle. I can run just the muffler (as a dump) which is leagle as long as it goes behind the rear axle. When I put my tips on, it actually makes it quieter. It's because the more pipe you have, it will absorbe more sound.

A larger diameter tailpipe will make your stang have a deeper rumble, not necessary louder, just deeper in tone... while smaller tailpipes will make your stang have a higher pitched exhaust tone, and sound a bit louder than the larger dia. counterpart...