What do you guys think? I seen both styles offered on the catylytic converter assembly. Which should I get? I currently have pre-cats on it now. If I get the assembly without the pre's, will I be decreasing backpressure and need to adjust anything fuel/air releated? Previous owner hacked off the flanges on the pipes to connect the resonator assembly to it and I need to either weld the resonator to this, or get a new cat assembly.

Opinions appreciated.