as the title says perferbly 3 inch but 2 1/2 will be fine too.

 

Fleabay is an option make sure the ends are rolled so you don't pop them while boosting.

 

still looking think my best bet is gonna be ebay

 

Boost logic although expensive is great because there is an indented lip on each end where your coupler has to slide over and the clamp sit on other side not being able to slip off. Not to mention that the piping fits exactly and you only have 2 couplers in the middle (Less the better)

 

cheacked it out and they seem pertty good .unfortunately too much for my budget i got one off ebay for 100 bucks it will have to do the job for now