In order to get good mph, I need to lock mine on top end of 3rd gear. Unlocked, I did lose mph switching from a 12" to the 9/11 but I was able to spool the bigger turbo with the 9/11. If I lock too early, it bogs until the RPM's get back up there. I dare not lock on 2-3 shift as I have a pre-billet trans. Here is the queston of the hour.... How does one check to see what stall their 9/11 is? I have seen and heard of the mash the brake and hit the throttle and see what RPM the tires spin however that would mean if I put bigger brake shoes on, I automatically have a higher stall convertor. How do we check?