Stock pipe size?
 

Sorry guys for the n00b ?, but i wanted to get some qtp elec cutouts and i want to know what size i need? im putting thme after the headers but before cats. what size do i need 2.5 or 3?

also be SLP the bellow is it 3.5 inches and 3.5 or 3.5 and 3 1/4 inch. i wanted to know because im not getting one from store but from hardware ish place


thanksguys