You won't need the block off plate. We only did it to make sure we got accurate AFR readings. It's only a theory, but it could potentially lead to cooler running temps. The popping on decel on the older Ninja 650's and ER6's was due to the split air induction. AKA snorkels, that were in place to quieten it down. The Z650 had it's air box redesigned and doesn't have this issue. Worse case, run it stock. If it starts to suffer from the popping, do a block off. You'll drop another pound or two by gutting that crap out, if that's something that matters to you. Oh yeah, I also found that you DO NOT need the resistor on the smog pump harness. I removed it out of curiosity and haven't had any issues.