is the 3" better for our cars or the 2.5"? i noticed many people use 3 but it says the 2.5 is for our cars. also does the 3 inch fit properly with the adaptor?

 

I'm not sure which is "better", probably not that much a differencein your beginning stages ofmodding. Most of the catbacks I see, don't even go all the way to the cat. They simply attach to pipedownstream of thecat where it's still 2.25"id. The Edelbrock catback (made for the Z28 with single cats), I have fits right up to the cat. The outlet of the cat is 3"id, then quickly gets reduced down to 2.25"id. We simply cut off the reducer and welded it to the now 3"id opening. I don't have any experience with any other catbacks, so I'm not sure how they mounted up.

 

the 3 inch is the z28 one and the smaller one is for the 6 poper....

 

True, but you can make them fit which ever one you want.

 

the 3 "in will create a deeper sound however th 2.5" will likey give you a higher preformance gain

 

I have read that there is no noticeable gain from either of them. There was awrite up in a mag (GM Proformance, HotRod???) They said there is possible of 1-2 HP gain from 2 1/2 to 3". So before you spend an extra $100 to change your mid pipe, just change the muffler to the brand/sound you like.

 

well im having a cutout put in after the cat n then the flange cut off the catback and all welded together so it dont matter if it goes all the way or not because im having it all 3". i just wanted to know which people was thought better for sound. im just goin to do i/h/e on it and im throwin gout and replacing it. steering rack and pinion, driveshaft, differential, literally everything. motor wise im just getting a ls1 next year so i just want i t to sound good. clearwater headers, magnaflow exhaust and custom intake. thats it. only other mods are going to be strut tower, drop .5 inch, c6 zo rims, n shocks n struts. what ive done in the past is as i replace worn out items i upgrade them. i also do everything but welding myself. thnx for the input

 

Nothing against you, but I don't believe you're going to swap in the LS1. You didn't even know if you should keep your "custom" intake behind the radiator fan or not. Lots and lots of people come on here asking what it would take to swap to a V8, and not once has anyone talked about having gone through with it. Plus swapping in the LS1 only to put an intake and exhaust on it, is rather foolish. For what you paid for the six, and what you're going to pay for the swap, you could have purchased a Z28 and had plenty of money for mods.

 

i bought a six now because i need a daily driver. and like i said i dont want to do a swap till next year so i have my christmas bonus and income tax return for about $2 grand total to put towards it. i thought the intake behind the fan would be a good idea since the fan blows cool air in so i figured it would be good for a cold air. but i decided ill buy a whisper lid and see if there is a difference. as for the v8, i just want a nice sounding car that i can take to the track on weekends. thats y i want the v8 with mnimal mods. im being practical since doing a ton of mods gets u just horrible gas mileage and i only want to own one car right due to insurance. 19 year with cars would be in the 7 or 8 hundreds and i definately dont want to do that. i dont plan on owning 2 cars till im 25 so my insurance will be cheaper and i can afford it then.

 

What I suggested just getting the LS1 to begin with skipping the six. True the fan is a cooling fan, drawing in cool air, but the radiator warms it up. That lack of knowledge is what leads me to believe, you won't do the swap. All I'm saying is you could have purchased a Z28 for cheaper than what you are talking about doing. You wouldn't even have to spend the money you saved, on mods. You can put it towards your insurance. I was just throwing out ideas.