I had a tune installed by Pmp motorsports here in Austin,tx for my 03 Lightning. The tune is for a 6lb lower and stock upper, ported c&l, single blade, cai, borla cat, sct2600. I noticed i was only seeing 11lb of boost. He stated i should be around 13-14. So i measured the pulley and its a 4lb. Can i install the 6lb and be ok since its tuned for it?