GV Under/Overdrive Units
If you have all of the clutch gear in car I recommend the Tremec TKO600. It cannot be broken. We have been runing a TKO500 for ten years behind a 425 h.p. crate motor. Runs 12.60's all day and cruises like a dream. We are upgrading to a 600 because we are pumping up the power to 560 h.p. Let er rip.