New best...The good, the bad, and the ugly. **UPDATE**

Was out for the first time of the season last night at Pacific:

The Good:
Car ran a new best and I dipped my toe in the 11-second streetcar pool. 11.92 @ 111+. It hit harder with the new converter and cut over a tenth off my previous best 60' @ 1.65 (previous best 1.78).
As usual at the track, met nice people, and ran into a few friends, and had a great time.

The Bad:
Could just be the heat (over 80 yesterday with heavy air). but it was down on MPH by about 1.5 from previous best. I was suprised with this, because one of the changes I made over the winter was a sealed fresh air system that I thought would be worth a couple of MPH. Maybe I just need to play with jetting (???).

The UGLY:
Had to push the car onto the trailer..... last run resulted in a broken rear end. I just rebuilt this 8-3/4" in the fall, and it had been quiet and acting just fine until the fateful last run. launched and made it about 5 ft before BANG. Some of the guys that pushed me onto the trailer said they thought maybe it was just an axle because it wasnt making any ill sounds as they pushed it (???). I'll get it apart sometime soon and post the carnage.

Posted By: 383man

Re: New best..... The good, the bad, and the ugly. - 07/30/12 06:57 AM

I have had a Detroit Locker in my 63 for almost 4 years and no problems. I dont race alot but I race it a few times a year and its still holding up fine. Course I do plan a Dana in the future when I can afford it. Ron

Posted By: Thumperdart

Re: New best..... The good, the bad, and the ugly. - 07/30/12 05:05 PM

Quote:

well, I got the rear end apart today. No such luck with the axles... they were fine. It was the differenial (again). Side gears in the powerlock unit broke just like last year. Looks like I was extremely lucky though, as somehow there are pieces of gear laying in the housing but nothing got into the ring & pinion, so I should be able to re-use my 3.91's (if I choose to go with the 8-3/4 again???... I've got an offer for a Dana on the table as well.)

Can you say spool? Been driving racing w/one for years in my WEAK 8 3/4 w/30 spline Dutchman axles..........

Posted By: Triple Threat

Re: New best..... The good, the bad, and the ugly. - 07/30/12 05:57 PM

Quote:

Can you say spool? Been driving racing w/one for years in my WEAK 8 3/4 w/30 spline Dutchman axles..........

His car is a bit much of a street car for that. And with stock axles and a heavy car I don't think its a good idea. I have a spool in my car, It can be done, but you can tell its there and I don't think its the right decision in this case.

My dads challenger lunched two 8 3/4's before he switched to a dana, brothers car also killed 2 center sections before switching. Both were high 11 second cars as well, stock but rebuilt center sections. I made the switch before reaching that point.

IMO if you plan on keeping the car for a long time, a Dana is the way to go, albeit more expensive in the short term, probably a worthwhile investment in the long run. The locker ($500) in your 8.75 might get you bye but you still have stock 30 spline axles and the small R&P as a weak link. Axles are another $300.

If you need a center section until you decide what you want to do, I have the one out of my dart, 3.91's, just sitting here you can borrow.

Posted By: Thumperdart

Re: New best..... The good, the bad, and the ugly. - 07/30/12 06:02 PM

Good points............what works for some of us doesn`t work for all and stock axles don`t belong in many of the cars on here in my opinion.

Posted By: Polarapete

Re: New best..... The good, the bad, and the ugly. - 07/30/12 06:38 PM

The offer still stands. The Dana is just resting in my garage and taking up valuable space. The project can be a lot cheaper than $1,200.00! I can clean off the axle tubes (remove all existing mounts) and I have an industrial chop saw that can cut the tubes squarely to your specs. New Spring perches are cheap and you can get 8 3/4 / Dana billet housing ends from Morrison for under $150.00, then reuse your existing brakes, bend some new brake lines. This unit has a rebuilt PowerLock diff with 4.10s (the stongest OEM LS), but I don't know the spline count. I do have another rebuilt PowerLock with 30 spline spiders and you could have that as part of the deal and reuse your 8 3/4 axles. You and I can do most of this together and the only thing you will need a pro shop to do is to jig weld the housing ends to the tubes, shorten the drive shaft and match the pinion yoke. And I am willing to wait for my money or do some trading.

Posted By: Triple Threat

Re: New best..... The good, the bad, and the ugly. - 07/30/12 06:44 PM

Narrowing is $150 job, I can give you the number to a few different shops locally that will do it to your specs.

Posted By: dragram440

Re: New best..... The good, the bad, and the ugly. - 07/30/12 07:24 PM

Going on 3 years on my 8 3/4 running 10.60-10.70 in a 4000 lb car running high 1.48 to 1.50 60' and havent had a problem yet. Just put a spool and 35 spline axles and you will be good to go.

Posted By: Cab_Burge

Re: New best..... The good, the bad, and the ugly. - 07/30/12 07:28 PM

I have a Dana 60-2 that came out of the front end of a 4 wheel drive pick up in a junk yard, it has 2.5 inch diamteter axle tubes, not 3.0 inch

I was planning on having new chromemoly axle tubes installed in it, it was hit by a train and bent the original tubes badly, by Dutchmen but changed my mind when I was able to buy a regular Dana 60 pick up rear end for $200,00 out of a Dodge 3/4 ton van

I use to buy Dana 60 out of junkyards in the past tha had a bad end on one side for $75.00, some had posi and 4.56 ratio

Others did not have posi or desireable gear ratio, some had bad gears

As far as the axle splines the later, up to 1970 I think, GM Dana 60 had 30 spline axles in them stock, the 8 3/4 axles slide right in

Posted By: Polarapete

Re: New best..... The good, the bad, and the ugly. - 07/30/12 08:11 PM

The rear that I have is definitely a Dana 60-2 (cast 60-2)and I measure the axle tubes as 2.875. I understood that front Dana 60s were OEM reverse rotation and only found in 1 ton and bigger 4x4s and for that reason they were marked as "61", but I have never seen one myself. Pete

Posted By: Cab_Burge

Re: New best..... The good, the bad, and the ugly. - 07/31/12 05:38 AM

Quote:

The rear that I have is definitely a Dana 60-2 (cast 60-2)and I measure the axle tubes as 2.875. I understood that front Dana 60s were OEM reverse rotation and only found in 1 ton and bigger 4x4s and for that reason they were marked as "61", but I have never seen one myself. Pete

The Dana 61 where used in 3/4 ton trucks two wheel drive rear ends, mainly the 1973 to 1976 or so 360 FE engined powered commercial Ford truck fleet orders, with the 3.30 gear sets, I turned one down that was free years ago

I have tried to contact Dana customer support to see if a regular rear end gear set will work in mine, no luck on contacts, another reason I haven't pursued using it

Posted By: StealthWedge67

Re: New best..... The good, the bad, and the ugly. - 07/31/12 03:57 PM

This sucks. I'm not sure what to do..... I know that going the Dana route is what most will suggest, but I really do believe that an 8-3/4" with a Detroit TruTrac diff and a set of aftermarket axles is going to stand up to my car just fine, and I can do all of that myself for under $700. I don't plan on going too much faster, as I really don't want a roll bar in this car.

The diff that broke was a rebuilt powerlock unit in the same case that gave me trouble last year. I called Eaton yesterday, and the tech there said that the Detroit TruTrac will handle everything I can throw at it at my cars performance level.

The issues with the Dana are all the small stuff that adds up. Brake lines, axle tube ends, axle redrilling, shortening my driveline.... I don't see myself getting out of that project for much less than a grand. The other issue is that it's got 4.10's in it. I really don't want to go DEEPER than I have now. 3.91's are steep enough!

Sorry to make you wait, Pete. and thanks so much for the offer to help. I really do appreciate it! I'll have a decision made here soon. Feel free to add any advice you may have to confuse me even further...

Posted By: cgall

Re: New best..... The good, the bad, and the ugly. - 07/31/12 04:36 PM

If you haven't already, put a back brace on it. Get your new locker and axles and forgettaboutit. The ring gear teeth are the next weak link if you decide to step up your power level.

Posted By: Thumperdart

Re: New best..... The good, the bad, and the ugly. - 07/31/12 04:36 PM

I`d stick w/the 8 3/4 myself and I guess you could add the one billet cap and some good axles..............how much does it weigh w/you on board. And as said above, a back brace..........

Posted By: 383man

Re: New best..... The good, the bad, and the ugly. - 07/31/12 04:50 PM

How much do you race the car ? Ron

Posted By: StealthWedge67

Re: New best..... The good, the bad, and the ugly. - 07/31/12 07:10 PM

Ron, Which Detroit differential do you run? There's the "locker" which I understand is not suitable for street driving, because it clunks obnoxiously when pressure is applied and removed from it. Then there's the Detroit TruTrac, which is what I'm considering.

I typically get to the track 3 or 4 times a year, Ron, and I do enjoy racing the car. I want it to be able to handle the stresses of running mid to high 11's.

Last time I weighed the car, it was at 3770 with me in it. That was before the new motor which has alum. Heads and the split mono springs. I'd guess it at about 3725 right now???

How much are billet caps, and can I bolt those right on? Or do I have to have the case machined to accept them?

Posted By: Thumperdart

Re: New best..... The good, the bad, and the ugly. - 07/31/12 07:13 PM

I`d check on cap prices as I still run stock ones

and they do have to be machined/honed to fit. You are definately on the heavy side...........

Posted By: Cab_Burge

Re: New best..... The good, the bad, and the ugly. - 07/31/12 08:22 PM

Quote:

How much are billet caps, and can I bolt those right on? Or do I have to have the case machined to accept them?

Call Mark Williams for the caps and prices

The caps have to be machined to the case, no machining needed on the case

I've had them done and then a local machine shop here in Bend, THANKS John Prehn

,let me use his Sunnen rod machine to machine the caps to fit

Mark Williams provides the I.D. needed for tha cap, cut it down to fit and your done

Posted By: Thumperdart

Re: New best..... The good, the bad, and the ugly. - 07/31/12 09:04 PM

Good to know Cab on the machining on cap only cos I`ve been told the case needed attention too to make sure it`s perfectly round. I assume you`d use a dial bore gauge after grinding/torquing cap to verify roundness no?

Posted By: dragram440

Re: New best..... The good, the bad, and the ugly. - 07/31/12 09:08 PM

I also run the stock caps. Yes Im probly asking for trouble but it has been working good for the last three years. My car really doesnt 60' very good so im thinking thats probly why it hasnt broke.From the info everyone on here it is way past its life expectancy!

Posted By: Thumperdart

Re: New best..... The good, the bad, and the ugly. - 07/31/12 10:04 PM

Quote:

I also run the stock caps. Yes Im probly asking for trouble but it has been working good for the last three years. My car really doesnt 60' very good so im thinking thats probly why it hasnt broke.From the info everyone on here it is way past its life expectancy!

You and me both........

every pass..............

Posted By: 383man

Re: New best..... The good, the bad, and the ugly. - 07/31/12 10:41 PM

Quote:

Ron, Which Detroit differential do you run? There's the "locker" which I understand is not suitable for street driving, because it clunks obnoxiously when pressure is applied and removed from it. Then there's the Detroit TruTrac, which is what I'm considering.

I typically get to the track 3 or 4 times a year, Ron, and I do enjoy racing the car. I want it to be able to handle the stresses of running mid to high 11's.

Last time I weighed the car, it was at 3770 with me in it. That was before the new motor which has alum. Heads and the split mono springs. I'd guess it at about 3725 right now???

How much are billet caps, and can I bolt those right on? Or do I have to have the case machined to accept them?

I run the Detroit Locker. It has a little clunk sometimes but nothing that bad. You just have to know not to lay into it when you make a turn until you straighten it up so the axle locks back up. My car weighs 3700 lbs and I put 7 passes on it last year with the new eng. The Locker is the only part in my 8-3/4 thats not stock. I still have stock axles and caps. I did not update it as I plan to go to a Dana when I can afford it. Also my rear is not braced as I did not worry about it when running mid 11's since I only race it a few times a year. Even running 10's its holding up fine but I think I am running on borrowed time. Ron

Posted By: Sledge_57

Re: New best..... The good, the bad, and the ugly. - 08/01/12 02:16 AM

My car has had a locker in it for years, once you get used to that little wiggle that other Locker owners will understand

(if you get off and on the gas slightly you'll feel it) it's fine on the street.

But like Ron said you gotta be careful applying power out of a corner or through a corner for that matter, sometimes my happy foot locks the rear end up half way through the turn...

As for the clunk it's just another noise you'll get used to.

Posted By: Cab_Burge

Re: New best..... The good, the bad, and the ugly. - 08/01/12 02:34 AM

Quote:

Good to know Cab on the machining on cap only cos I`ve been told the case needed attention too to make sure it`s perfectly round. I assume you`d use a dial bore gauge after grinding/torquing cap to verify roundness no?

No dial bore gauge on that, Craftsman inside mike and outisde mikes is what I used 5 years ago

I started out cutting the steel cap very slowly, cut it three times instead of making it to small with one cut

I cut it, machine the cap, a bunch of times and ended up getting in a hurry at the end and made it on the small limit, it worked out real well

I have two of the Mark Willams steel caps left, one will go in my Dart rear end when I set the new OEM Mopar 3.23 gears up and swap out the stock 741 case with the 3.91 gears. Not sure what I'm going to do with the other cap, now that I have swapped over to the Dana 60 in the Duster and have one for the new full tube chassis Dart

Posted By: Thumperdart

Re: New best..... The good, the bad, and the ugly. - 08/01/12 03:02 AM

Right now I`m gettin my classes together at VVC so the car`s under a cover and doesn`t exist

but I may get that from you.......

Posted By: StealthWedge67

Re: New best..... The good, the bad, and the ugly. - 08/02/12 04:23 AM

Well, I've talked to two rear-end guys now that I contacted to do the narrowing and fabbing with the Dana. After talking to me about my car, and desired performance level, Both have advised me to stick with my 8-3/4", and just put a backbrace on it, and a good differential in it. Both suspect that the powerlock case that has been at the center of both of my failure's in the past year was faulty. Cass (Dr. Diff) also had concerns about my case last year when I bought the rebuild kit.

I think that's the direction I'm gonna go. Thanks SO much to PolaraPete for the awesome offer on the Dana. I feel bad that I'm not taking him up on such a friendly offer. Guys like Pete are why this hobby is so fun. I hope I get to meet you some day, Pete.

Posted By: gregsdart

Re: New best..... The good, the bad, and the ugly. - 08/02/12 01:12 PM

I don't know if it is done much, but load bolts for the bearing caps might be worth looking into? Also I got away with the same driveshaft years ago going from an 8 3/4 to a Dana. It was very tight, but there was enough room for it to not bottom out. Don't know if you would have the room, but would be worth measuring. If it doable but tight, an engine limiter to keep the engine from moving back and forth would be a must.

New best...The good, the bad, and the ugly. **UPDATE**