Pretty sure the reasons the Pro Stock teams switched from Lencos to geared transmissions was less internal drag as well as lighter weight. I was talking to a fellow Ford racer, who until recently raced a Comp Eliminator Ford Probe, as well as a 8 second 67 Fairlane, and he told me his old Lenco 5 speed was about 8 hundreths slower in the 1/4 mile than his current Liberty clutchless 5 speed. In Pro Stock, that .08 can mean the differance between qualifying in the top 1/2 of the field, and not qualifying at all.