With only 405 HP, use 1.625" long-tubes, dual 2.5" is more than enough, and forget any 3" parts.
You could make it easy on yourself and just use Hooker's 2.25" dual exhaust with their matching headers. Still plenty of flow for no restriction past 440 HP, if you choose mufflers wisely.
Thanks for the advice. Would the 1.625 headers give me more power on the top end?