I have a rooted verizon gs4 running the 4.3 update and safe strap. If I install the pure google rom on a second rom slot will it brick my phone?
EDIT:
What about the hyperdrive rom?
Do you mean dual booting your phone? if you're partitioned properly and the devs for your phone have supported dual booting, then you should be okay. Just look around XDA, find a tutorial on how to dual boot your phone, and follow the instructions EXACTLY how they are written. If you aren't comfortable with the instructions then don't do it, you're better off running stock than bricking your phone.
I got hyper drive running and I still have the stock rom.