35th camaro

How much can i expect to lose after installing the larger 60s diff, i did dyno 457 rwhp on my 402, it's going to be hard for me to tell because i am also upgrading from a the stock ls6 intake, t/b and 85 truck maf and slp lide to a fast 102 intake, 102 t/b , 100mm maf and 104mm lide at same time over winter.

cowboysfan

probably not much due to the upgrades....

2nd Gen Fl 'bird

iTrader: (13)

IIRC, Car Craft did a dyno comparison with the Dana, Ford 9 inch, GM 12 bolt and stock 10 bolt. Can't remember what mo/yr. 12-15 more hp seems to stick in my mind on the additional power usage on the heavier rear ends. All(aftermarket) were in the same ball park. Just bigger/heavier parts.

KurtRardin

iTrader: (11)

Not enough to be concerned with. My S60 helped me hook up a lot better than the ol 10 bolt. All the extra weight is in the perfect spot IMO. The carcraft article also shows the cars with the S60 trapping higher speeds, which would be an indication that they're hooking up better.

Your car is making enough power to destroy a 12 bolt if you have a monster clutch and sticky tires. If you're looking for an atom-bomb-proof rear end then you should be looking at either the S60 or a Fab9 from Midwest. The S60 will force you to get a new driveshaft, but it's all good because the overall cost for the complete bolt-in package with every single option and a PST driveshaft will still be cheaper than any other option. If you got it with a spool then it would be even cheaper. It was the cheapest fully bolt-in street option when I purchased mine anyway; over the 12 bolts, 9 inches, and fab 9's. Being forced to get a new driveshaft is a good thing because it removes the aluminum shaft from the list of potential problem areas. You won't be breaking a PST shaft... Ask for that one specifically.

It's such a great bolt-in piece too. Since the Torque arm mount is cast in the rear end it looks like a factory piece... and fits like one too! To me it fits like a rear end meant to be paired with a factory LS7.

The only way that I would be concerned with how much power the S60 robs is if I had to compete in a class where you couldn't modify engine parts. You couldn't make me trade for another rear end now. If you get one then you won't be disappointed. Call Eric at MidWest Chassis for a great deal.

35th camaro

Kurtradin do you have a aluminum rear cover on your diff, if yes do you have any clearences issues? they told me i could not order it with the diff.

zracer323

iTrader: (12)

http://www.gmhightechperformance.com...e_changes.html
Check out this link. In this test the S60 lost about 2.5% more hp than the M9 and weighed nearly 20 lbs more.

KurtRardin

iTrader: (11)

Are you talkin about the performance cover with bearing cap supports? No. And from what I've read it's almost not even necessary. The bearing caps are massive on an S60.

Here's the cover I've got on mine. It's powdercoated in gloss, and I hit the whole rear end with flat black.

35th camaro

nice. so you don't have an issue with the basic alum. cover from strange? i was interested in the supporte cover only for the WOW factore, was only a couple of bucks more. and at my power level did not realy need it. any body else running the basic alum. cover

96lt4c4

iTrader: (5)

That Harbor Frieght racing jack is bad ***, I have the same one......Just kidding that a nice looking rear end too.

KurtRardin

iTrader: (11)

Man I think you'd be hard pressed to find anyone who's broken their S60. I know of a few (like two) people who've had trouble out of their truetrac, but I think they were factory defect issues and not an issue with exceeding the power threshold. The truetrac used in our Dana 60's are 35 spline units, not the typical 31 spline units that people complain about. 35 spline axles on a 450rwhp car is very overkill, but it's the only way S60's come. That's why they're viewed like an urban legend.

If you're building a bracket racing car then you'd probably be better off going with a spool. It'll weigh less and then you'd need more than 2000 hp to start breaking stuff. Get the chromemoly yolk upgrade too. It's cheap.

If this is just going in a street car then the truetrac is fine. They handle well, don't make any noise, and provide excellent traction.

Chrysler had the right idea using Dana 60s with thier big blocks. They knew they needed something strong to handle the torque from the hemi's and 440's. Plus, if you look under some of the outlaw cars you'll see some dana 60's.

I kinda doubt that strange would recommend anything other than a spool if you called them up asking what parts you'd need for an S60 in an 8 second car.

KurtRardin

iTrader: (11)

I used to be a manager at Harbor Freight. You can't beat that jack, and honestly their tools aren't that bad either.

35th camaro

i think you got me wrong, i kno i won't have a probleme with the dana, it is the clearence of the alum. cover with the under car issue i may have, my dealer that is getting the dana for me said that strange would not put the cover on because of clearence issue, mayby he misunderstoud.

KurtRardin

iTrader: (11)

Ah, I think I gotcha. I think you run into clearance issues with the upper phb. The regular cover is close. If there were bearing cap supports it would be really close. This rearend is shoehorned in there!

35th camaro

when you say the regular cover you mean the alum. strange black cover that seems to be on yours, you say it's close but ok ?

KurtRardin

iTrader: (11)

Oh yeah, the cover I've got fits fine. No problems at all. If you don't order that one then you get a chrome cover, which in my opinion looks kinda cheezy. They probably don't want to sell you a "performance" cover though, which is a whole different animal than the cover I've got. I think I saw someone on here that found a company that makes a performance cover that's low-profile enough to fit. There's really no need for it though. If you're looking for a sweet looking cover id just stick with the upgrade aluminum cover like I got. I think it was something like $65 more.

35th camaro

thanks, i will tell them to add it to my diff. and if not i will order one seperat.

KurtRardin

iTrader: (11)

Who are you ordering it thru? If you're going thru Eric then ask for the PST driveshaft. I think it was a little cheaper than the strange option.

SmokedOutZ28

iTrader: (35)

I lost about 15rwhp when switching from 10 bolt to s60 with no other changes. BUT I was able to gain 1 full sec in the 1/4 mile because I could launch harder and actually shift the car like I wanted and not worry about breaking the weak 10 bolt.

I was also told by strange that they stopped selling there support cover because of complaints of it hitting the gas tank but I ordered a aftermarket one and have not had any issues at best the support bolts might hit the phb but thats all.

Paul Bell

iTrader: (9)

I forgot where I got this from but I've been saving it for just this question.

I would think that the nine inch rear can be had just as strong as the S60. The S60 is a very heavy rear.

KurtRardin

iTrader: (11)

To make the 9" as strong as the S60 you'd probably have to have a backbrace welded on plus run 35 spline axles. Those things are easy enough to order but that starts driving the price up a bunch.

The only plus to having a 9 inch IMO is being able to take the center section out and either work on it while sitting at a bench, or the ability to have multiple centers set up with different gears/posi's. It would be freakin awesome to have a 9" with a 3rd member set up for highway cruising: 3.42's and a trac-lock; and then one set up with a spool and 4.30 gears for the track.

Changing gears in a non-3rd member rear end is a pain in the *** Unless you're willing to do the surgery then you're pretty much stuck with the gears you pick.