I see all kinds of opinions, but they are just guesses. Not one response from anyone that has bought/used one. A friend and I each bought one. Haven't used either one yet, but visually they look OK. Mine will be replacing a spool with 3.91 gears, that will be going in a street driver modified slant six, in an "A" body. Not like I will be making 600 hp (maybe 200-225 hp). So figured I would take a chance. Don't want a spool on the street. Hopefully will have it done and in the car by early spring.