At the momen I have a full micron exhaust from midpipe back. I have a turndown that has a baffle on the way. I've read that some people don't get enough back pressure and can ruin valves. I was thinking about putting a baffle in the end of the midpipe to make up the difference to makeup for lost back pressure. I have a fi2000 programmer with k&n filter kit. Any one have any other ideas.

 

As long as you have the exhaust manifold/headers in place your valves will be fine.