What is the differnce? They make a 18, 16, 14,12 inchs and so on in legnth. Also don't forget the out let sizes 2, 21/2, 3, 31/2, 4 inch. What about out let designs you have oval, bowtie, side by side round and on. What about what is called dumped after the exhaust? Dont let me forget about the angle cuts of diffrent tips too. What I want to know is what does it all mean? Is one better than a other. If I go to a shop they will only try to sell me what they have in stock. So I would like to hear from people that have nothing to gain. I have a 99 xcab 4.2 with only two cats and a fake flowmaster 40 on it. This is with the stock exit. Thanks Ben

 

Don't forget about the type of material also. There is stainless steel and chrome plated steel. Chrome or polished tips are mostly for looks, and can alter the sound of your muffler only a little bit.
First, there is your inlet size which is the size of your current exhaust pipe. Probably 2 1/4 to 2 1/2 inches.
Second, there is the outlet size, which is the size of the pipe where your exhaust gases exit. The most popular sizes are 3" to 4".
Next is the length, which is mostly cosmetic. However, when a large outlet diameter combined with a long tip is used, the sound of your exhaust exiting is magnified a slight amount. It is like talking through a cone-shaped megaphone (it increases the sound of your voice and projects it further.)
Lastly, a dumped exhaust is turned down or 'dumped' immediately after the muffler with no need for fancy looking tips.
An exhaust shop is going to sell you whatever you want, as long as they have it in stock.
I would suggest searching the forums for pictures of exhaust setups and find out what you like.

 

aFewScrewsLoose. Which tip would help give me a bit loader sound. I am looking at a 18inch long 21/2 inch inlet 31/2 inch outlet. Or would it be better to just dump it?What would that do for me in sound? Thanks Ben

 

if you're just going straight out the back you don't need more than 12" tips cuz you can't see them, if you go out the corners I'd go 18" cuz you see all of it. jmo though

 

i have 18's 2 1/2 to 3 1/2. angle'd at 45 degrees. personally imho i like that better than straight out the back cause when you go past buildings it sounds awesome and it just looks really good. but when you get tips. get stainless steel.

 

Brads984x4. I do have my eye on a 18in, 21/2 in, 31/2 out with only a 5degree cut rolled end. Its a magnaflow tip for about $30. I do plan to have it exit out the side passed the rear wheel. This should add to the sound that my fake flowmaster 40 exhaust gives out right? Ben