so I am new to this site, i have an 87 monte carlo ss with a 305. I'm working on the exhaust and i have it straight piped from the cat back. Now i want to add cherry bomb glass packs (2, 8" ones) on there. I also want to make it louder by hollowing out the cat. is it ok to do this without harming anything? it has the emission system stuff (EGR1 i think) it only has 1 O2 sensor before the car. So if anyone has ideas for me please help, thanks!