[niles]

Jim: that not helpful!

Make sure you have set/welded your eng, mounts. where you put your eng(fore/aft) will effect where the pipes exit.

Set eng first; place body on with headers : no side pipes and sight and scribe where the header buddle intersects body. cut very slowly and allow about 1/2 all around. maybe 3/4" above pipes for allowing for pipe movement due to eng torque.
Go slow; it's easer to slowly enlarge cutout, than reglassing body when you made it too big. trust me on this one; been there/done it!

gn