1966 Buick GS 455 Stage 2

Getting ready to change my exhaust from a 2 1/2 inch system with FlowMasters to a 3" system with Dynomax Super Turbos. Car runs 11.2 @ 124 in the 1/4 mile as shown...street tires and closed exhaust. 455 with aluminum T/A Stage 2 heads, T/A roller rockers, T/A SP1 intake, Edelbrock 800 cfm carb, headers, MSD ignition, CompCams .517" lift cam, Fresh short block. THM 400 with Gear Vendors OD unit, Ford 9" rear end with 4.10 gears