sonic

i'm going to order some twice-pipes for my atomatic 240z tomarrow. i already got the 6 into 2 jetcoat headers, and i was thinking that i would get them installed at the same time as the headers. after all i wouldn't want to weld a 2.5" collector to my current smaller diameter stock exaust. besides i want the sound!

what are the problems with the msa twice pipes? will they harm my 2.4 l-6 engine in any way? and will i have any performance loss from stock? does it sound ricey?

thanks