92 F150 XLT 5.0FI w/ aftermarket dual exhaust (one pipe per exhaust manifold); I bought in Nashville TN about two years ago and there it passed the state emissions without OE catalytic converter(s). I've moved to Colorado where catalytic converters are required to pass emissions. I am looking for advice on installing CatConverts needed, if the installation of two CatConverts will prove acceptable and if so what spec and model of CatConvert will be required. Any advice is welcomed.

 

Magnaflow 94006 model cats two per bank would be good.

 

Correct me if I am wrong, but if I have a 5.0L engine and one exhaust for 4 of its 8 cylinders, why would I require a CatConvert that would accommodate a full 8 cylinders for a much larger engine as you have recommended, and two Magnaflow 94006 per bank? Would I not want a CatConvert that would accommodate half of the exhaust capacity (each exhaust)?