MeanMonte Posted December 5, 2007 Share Posted December 5, 2007 I am going to upgrade the rear in the monte this winter. Right now i am looking at Moser 9" housing with a nodular center, 31 spline truetrac and 3.55 gears. The other option is a Strange s60 with 35 spline truetrac. They both have advantages. The truetrack with 35 splines in the s-60. The 9" has less weight and easier gear setup however is only available in more than 31 splines with a detroit locker or spool. I think i want to stay away from the detriot locker because of the driveline slop associated with it. What is everyones opinions? Thanks again Eli Quote Link to comment Share on other sites More sharing options...
Guest Phils72 Posted December 5, 2007 Share Posted December 5, 2007 I know from experince that it's hard to break a 9" 31 spline, but you have a good point about the detroit locker. I guess it really is up to you and the $$$ difference. Quote Link to comment Share on other sites More sharing options...
MeanMonte Posted December 12, 2007 Author Share Posted December 12, 2007 Wow I thought I would get more input on this. The 9" truetrac looks to be a very frail peice. I am leaning towards the s60 and after talking to their rep on the phone im very impressed. My only undecided factor is lack of feedback on the s60 and the ease of assembly and setup of the ford 9" Quote Link to comment Share on other sites More sharing options...
Guest 72yellowmc Posted December 13, 2007 Share Posted December 13, 2007 9" is more practicle, ya i figure some rear end guru's would chime in here. Quote Link to comment Share on other sites More sharing options...
Sam (Bones) Posted December 13, 2007 Share Posted December 13, 2007 most here are using 12 bolts, not many using a ford 9" I will have a ford 9" eventually, I will use a detroit locker for mine, but that's me Quote Link to comment Share on other sites More sharing options...
Heckeng Posted December 13, 2007 Share Posted December 13, 2007 They both look like good rear ends. I personally would probably go with the 9" and trutrac diff. What kind of power are you planning to make? The only time you'll likely need more rear end than the 9" and 31 spline axles is if you're putting LOTS of power to the ground with slicks, and in that case, you should probably be running a spool or detroit locker anyway simply because of power handling ability. What do you plan on doing with the car? Street mainly? Track mainly? If it's street mostly, stick with the 9" and 31 spline axles, if it's track, buck up and get the 9" with 35 spline axles and a spool or locker. Just my opinion! Quote Link to comment Share on other sites More sharing options...
John Burns Posted December 13, 2007 Share Posted December 13, 2007 I'm curious why you think the 9" true-track looks frail? I put one in my Camaro earlier this year. I haven't put a ton of miles on it, but it has a bunch of drag strip runs and it isn't treated kindly on the street- and so far so good. The car is a tank (3900 lbs with me in it) and it goes high 10s. http://store.summitracing.com/partdetail.asp?autofilter=1&part=CUR%2D9TT375S&N=700+400264+115&autoview=sku Quote Link to comment Share on other sites More sharing options...
Heckeng Posted December 13, 2007 Share Posted December 13, 2007 I have also heard that the trutrac is not as strong as say the eaton posi, or a detroit locker. Now I don't have any proof though. As far as design goes, I like the trutrac the best by far, and I've used similar diffs in the past and had great luck (Torsen differentials). The Torsen diffs are exactly the same as the Trutrac, and I would even bet that they sold their rights to Eaton/Detroit who now makes the trutrac. I'd love to see some proof showing that the Trutracs can hold up long term to lots of torque! Quote Link to comment Share on other sites More sharing options...
Zanie Posted December 13, 2007 Share Posted December 13, 2007 I went to your car domain page, but I couldn't read your dyno sheet readout for your engine. Are you running a stick or an auto? You'd have to have a pretty potent small block to hurt a 31 spline 9 inch with an auto. If you put 35 splines in when you don't need them, you are using HP to turn that stuff. I'd stick with the 9 inch simply because swapping gears is easy if you don't hit your mark the first time. Plus 31 spline third members are relatively inexpensive. For my 56 chevy I have two third members, one with a 4.10 for fun and a 3.00 for power tour and stuff like that. By the way give Doug at http://www.quickperformance.com/ a call he's a moser dealer. Tell him the HP you plan to run and he'll tell you what you need, he's areal straight shooter. You can get a bolt in 9 inch housing for $345 or the housing with axles, etc. for $715. Tell him Dan from Craftsman tools sent you. Good luck. DS Quote Link to comment Share on other sites More sharing options...
MeanMonte Posted December 13, 2007 Author Share Posted December 13, 2007 Ha cardomain hasnt been updated in forever. Thats an A/F log also.......... The money will be the same for the two. I want to stay away from the locker because I dont want to have the driveline slop when you put it in gear. The truetrac units for diffs other than the 9" look to be so much more beefy. I am sure it will handle the power I currently am running. I havent had it on a dyno yet but I'm guessing between 550-600 at the flywheel. The key is that I can continue to bump the power up in the future without adding parts to the setup. It is tuned in very mild and at only 7psi of boost(lowest boost I can set it at). It already has more power than it needs but thats not to say I wont turn it up later on. Both setups will be bolt in. I have to get a heavy duty driveshaft so that doesnt affect decisions. The S60 is a Strange remake of the dana 60 that has all of the mounts to bolt into an a-body I can get one for $2200 with the 35 spline truetrac. 9 inch would consist of housing 345 axles 300 bearing kit 125 nodular case 350 diff 425 gears 190 setup kit 120 pinion support 105 pinion yoke 110 total: $2070 I have diff experience and tools for setup so I can do that part myself. I just think for an extra $100 I get a heavier duty setup. The only downside is that its not as easy to setup gears in the future. BTW I have no facts but I belive the reason they dont make a truetrack in the 33 or 35 spline for the 9 inch is because they couldnt handle the torque that a 35 spline axle can. The same reason you cant use a disc type posi on high HP apps there just isnt enough room in the case. A spool is out of the question as the car is 75% street. The third member swapping idea is a possibility though. I do however have a 700r4 trans and the gearing is going to come down from 4.11 currently to 3.55's The 4.11 top out at 113mph in drive. I am looking for something to top out at 130mph which the 3.55's should, maybe even 135 if I take her to 7K. I bounce back and forth daily on this decision. I want the s60 for strength and maybe looks, but I want the 9 inch for changing around if I need to. Again thanks for your opinions! Quote Link to comment Share on other sites More sharing options...
MeanMonte Posted December 14, 2007 Author Share Posted December 14, 2007 From the tech person I spoke with you can only narrow it 7/16" per side without having brake problems. I belive a little more if you run the wilwoods. Problem is I have looked at ls1tech.com and the chevelle board and there are only a few people I can see running them. After I looked at all of the strange catalog I feel much better esp after seeing their topfuel type rearends! Quote Link to comment Share on other sites More sharing options...
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