exhaust ????

ok i need some helpo... on my 98 gmc non dually 454 i need to know how yours iss set up after the headers......... pics would be greatful since i can't rememeber where are the o2's and how do you guys ahve yours set up?? we dont have emissions or inspections so i jsut need ideas

question?
1) iss
2) headers if so long or short
3) how many o2's do you have on it
4) is your cat still on

and your o2's tell your ecm weather to run rich or lean

i dont reember and i need to send parts to trevor