You
do not want to use the MSDS headers in conjunction with the SHO y-pipe.
a) it voids the MSDS warranty
b) it sounds terrible (at least when I had MSDS->SHO y pipe-Bassani)
c) MSDS y-pipe (IIRC) provides more HP
Anyone getting the MSDS should seriously consider getting them jet coated. I know the "revised" coating is suppposed to be better, but I know there are a couple people with the "revised" coating that are seeing signs of rust:
MSDS "revised" coating rust pics. 
