mufflers on my duals for race application

so i am setting up my exhaust for the conversion of my camaro into a track car so i tore off the exhaust and am putting on pacesetter longtubes. i am definitely doing an x-pipe, but i am not sure which mufflers i should use for the best flow, or if they are really even needed. if mufflers are needed will the length of the bullet muffler restrict it. i know dynomax's are very popular and are relatively inexpensive, but there are a lot of other options out there that i am sure some people have explored.

i am also not sure if my track has a decibel restriction, i guess some do, i just wasn't sure how to get that information from them.

not sure if anyone could help me out, but that would be great

some classes require mufflers, kind of depends on the track though.

im running 3 inch flowmaster race mufflers. they are pretty low profile, and sound good.
alot better then my 3 inch bullets i used.
http://www.mofbody.com/blkchevyz/mufflers.JPG

i'm currently running a 3" Xpipe with no cats and no mufflers, dumped at the axles.

behind my cammed LS1:cool: it's loud

oh...and it's street driven...