2000 Gmc K2500 O2 Sensors?

[glanzergtx]

Hey guys,

 

I have a guy at work that just put a zz4 cam with 383 stroker kit in his 5.7L gmc. He also got shorty headers to go along with it. My question is what o2 sensors are needed? Obviously we would run the front too just because i dont want to command it to run open loop with my Hp tuner. Hes trying to get away without running CATS and the rear o2's. If i just delete the rear's would the pickup run just fine or does the PCM always look for a signal coming from them?

 

thanks