FTI SRLS46391 9.5in 4L80E/4L85E Billet Lock-Up Street Racer Series - LS - 3800 StallFTI Performance SRL Series billet lockup torque converters feature a computer designed, CNC machined billet front cover and a billet lockup piston making premature clutch wear a thing of the past. With custom stator designs and multiple blade angle pumps, stalls are available from 2,800 4,400 rpm. They are custom built to your exact needs and driving style. With furnace brazed and heli welded fins, severe duty sprague, and anti ballooning flanged