HELP!!! need cutout diameter for stock car

[First Spray777]

i was thinking about buying a cutout for my I pipe after the Y but i dont kno what size to get......i was thinking it was the 2.5 but i want to be 100% shure, i own a 02 z28 vert....soo? the say on ls1 tech to get a 3.0inch but??? now im thinking if just the opening is 3.w/e

[secondgearscratch]

i was thinking about buying a cutout for my I pipe after the Y but i dont kno what size to get......i was thinking it was the 2.5 but i want to be 100% shure, i own a 02 z28 vert....soo? the say on ls1 tech to get a 3.0inch but??? now im thinking if just the opening is 3.w/e

do you have headers?

[NHRAMAN]

3" is correct

[First Spray777]

no no headers,....just the stock shorties, but i want it on the I pipe soo its 3inchs right? lol....whats a good store also? my g/f orderd a LId from Ws6store.com n it hasnt gotten here yet (march 11th it said shipped) so i dont kno if i should buy the cutout fromt here

[doctorleevil]

just wondering what size worked for you. I have a cutout on mine but not sure what size it is. I want to add the electric valve to it but not sure on the size.

[0rion]

I see they told him 3" but I'm almost positive that the stock stuff is 2.5". Could be wrong but I'm pretty sure stock size is 2.5".

[secondgearscratch]

I see they told him 3" but I'm almost positive that the stock stuff is 2.5". Could be wrong but I'm pretty sure stock size is 2.5".

you are correct. i just measured the i pipe 2 days ago.

[RedRocketZ28]

The stock i-pipe is 2.75". 3" cutouts are perfect for stock piping, it slips over nicely and can be easily welded.