you built a 408 and soon as you get used to that your gonna want more. i always build for future improvement. go 3" and be ready for the future. these cars are load and obnoxious. thats why we love em.
Did this with two chamber Flows. Not bad,a pair of long case Dynomax Ultra Flo's ,flow as much or better & quieter. My .02....
Edit: Have you checked out the Summit/Jeg's mandrel bent exhaust pipe kits? Can be had with or without mufflers.(both 2.5 & 3.0 available).