











Which rear end?
I'm going to be going with the 9" since I will be drag racing it (no more than 5 or 6 times a year).
What is the best auto-x/street use unit. Posi, soft-locker, hard-locker, spool(yeah, I know this one's out)?
I want something that's going to give me optimum control while racing, but I love to street my car.
What do you have and what are your experiences? Would you go the same route if you were doing it again or not?
An HD Auburn is probably a little better initially, but wears out really fast when loading the diff while turning.
The Torsen works well and lasts
)Or am I completely wrong and Torsen DOES make a T2R for the 9s???
J's, do you think the 12 bolt will hold up to the much torque??? I'm not going to be drag racing much, but I'm a little uneasy about taking a risk.
An HD Auburn is probably a little better initially, but wears out really fast when loading the diff while turning.
The Torsen works well and lasts

Listen to Mitch! Unfortunately No TR2 for the 12 bolt or 9". If you are going with either of those the closest thing to a TR2 is a Detroit True Track but it still lacks bias by comparison. The only thing comparable to the TR2 is The Auburn Racer's Differential unfortunately it is an Offroad only piece you can read about it here. Also Note that is only available for stock 10 bolts or 8.8" ford housings which again leave you little option if going to a 9" or 12 bolt.
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For the people with 9", what posi are you using???
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Happy to discuss options with you.
www.stranoparts.com --814-849-3450
Results matter. Talk is cheap. We are miles beyond the success anyone else has had with the 4th gens, and C5, C6, C7 Corvettes,
10 SCCA Solo National Championships, 2008 Driver of they Year, 2012 Driver of Eminence
13 SCCA Pro Solo Nationals Championships
2023 UMI King of the Mountain Champion
www.stranoparts.com --814-849-3450
Results matter. Talk is cheap. We are miles beyond the success anyone else has had with the 4th gens, and C5, C6, C7 Corvettes,
10 SCCA Solo National Championships, 2008 Driver of they Year, 2012 Driver of Eminence
13 SCCA Pro Solo Nationals Championships
2023 UMI King of the Mountain Champion
www.stranoparts.com --814-849-3450
Results matter. Talk is cheap. We are miles beyond the success anyone else has had with the 4th gens, and C5, C6, C7 Corvettes,
10 SCCA Solo National Championships, 2008 Driver of they Year, 2012 Driver of Eminence
13 SCCA Pro Solo Nationals Championships
2023 UMI King of the Mountain Champion
My car makes 510 rwhp NA and 640rwhp with 775 rwtq on a 150 shot of spray.
Last year I exploded the spider gears NA at an autocross that had a high speed slalom and the 4.10 gears exploded at a drag TnT. That being said I have now upgraded the spider gears and put a solid cruch collar on the pinion to try to hold it together. BTW I also found out that I had twisted my Moser 33 spline axles with my 1.48 60fts on a 3880lb race weight.
With your hp this setup should work but I will tell you at an autocross it does not turn in as well as I would like it too. You have to wait for the posi to release and it is an abrupt release. If I had to do it over I would consider a TruTrac, it is similar to a Torsen and supposed to be much smoother.
That is about all I can tell you though from my experience.
My car makes 510 rwhp NA and 640rwhp with 775 rwtq on a 150 shot of spray.
Last year I exploded the spider gears NA at an autocross that had a high speed slalom and the 4.10 gears exploded at a drag TnT. That being said I have now upgraded the spider gears and put a solid cruch collar on the pinion to try to hold it together. BTW I also found out that I had twisted my Moser 33 spline axles with my 1.48 60fts on a 3880lb race weight.
With your hp this setup should work but I will tell you at an autocross it does not turn in as well as I would like it too. You have to wait for the posi to release and it is an abrupt release. If I had to do it over I would consider a TruTrac, it is similar to a Torsen and supposed to be much smoother.
That is about all I can tell you though from my experience.
You've got a lot more power than I plan to have with this engine. I'm hoping for around 425whp and 400ftlb. My race weight's going to be similar to your's, but I'm not going to have the 400 extra mind bending ft lb's of torque. Considering this, I might be fine going with a 12 bolt and getting the torsen t2r. I've always been one to try and over build the first time so I don't have to do it again though. Also, I thought the TruTrac was a soft locker and not a posi. I really don't want to get a diff that's not predicible. They always have a long slalom course set up on the course too. I think I might need to start a 12bolt and 9" poll. The 12 bolts seem to have better diff options but the 9"s are still stronger. ugh...
Thanks for all the help so far though!
www.stranoparts.com --814-849-3450
Results matter. Talk is cheap. We are miles beyond the success anyone else has had with the 4th gens, and C5, C6, C7 Corvettes,
10 SCCA Solo National Championships, 2008 Driver of they Year, 2012 Driver of Eminence
13 SCCA Pro Solo Nationals Championships
2023 UMI King of the Mountain Champion
Sam, I'm going to try and call you inbetween jobs.
LOL, got to pay to play and, unfortunately, that means picking up a second job for a while. My goal is 1 more year. That way I'll have everything done before I'm 25. Then my expense will be fixing what I broke, tires, and brakes.






