the whole point is that the car still needs to be started and run again for the first time without exhaust. I could care less about driving it down the road to the muffler shop I just wondered about doing another break-in/ring seal without exhaust. I remember the car before with 12:1 and you could hardly hear any engine noise it was so loud. :-)

I tamed down the compression to 11.25 or so. Just worried that if I had something go wrong like rod knocking (heaven forbid) that I wouldn't be able to hear it with open headers.