Thanks for explaining that to me. People here are so nice. I used to go to a different forum where some people were just plain rude. I went with the roots blower because I wanted the old school looks. This goes in my 53 1/2 ton Chevy pickup. I think 5 psi will be fine for me. BTW I have a Tremec TKO 600 5 speed and Frankland quick change rear end and Wilwood 12.88" disk brakes. 4 piston rear and 6 piston front. Thanks again for educating me.