8 3/4 chunk math - sticker shock

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nothing wrong with a 741 case, its all hog wash lol

i have a friend that ran a stout 340 4 speed in a dart, 8 inch slicks heavy clutch,,,beat the snot out of it never had a problem,,,

if you drive that 318 as an almost every day driver,,,and a stock tire size you could save your self soem money and find a 3.23 you will see a improvment over your current 2.76 gears,,

or forget about selling your 741 case and built it ,:toothy10:use what you have,,,

i recently built a new unit,,used a 489 case i had,,,ide perfer a 742,but didnt want to take apart a good set up,that ddint have a gear i needed at the time,,,i may sell it 4.56 gears 742 case,,repairable sure grip,,,

any way all new parts in the 489 case,,and used the crush sleeve,,not the eliminator,, new sure grip,,,motive 3.91 gears,,,new install kit,,all bearings and bolts,,,big u bolt yoke,,all parts bought from doc diff,,and local guy from this board did the ring and pinion set up,,,im into it for less then 800
 
godfatherofchry said:
MAN I get so tired of hearing about this case is better than that one.I have run them all and never broke any of them.I am sorry for being out of line but I just had to get it off my chest........Artie
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Yep!!

If you want to go with the perceived stronger case and clutch sure grip, you're going to pay.

The pinion size IS NOT the weak link in the cases. So that whole weak case point of view is useless. Nothing your 318 can do is going to hurt a 8.75 rear unless you do something dumb with it.
 
You cant hurt an 8 3/4 with a 318. Those diffs held up to everything a big block could dish out.

$$ price for that stuff makes me really glad I lucked out when buying my Dart. It came with the 742 and 8 3/4.I had no clue 17 yrs ago that the diff would be worth more than the car,lol!
 
build the 741 that you have, if you are concerned about resale value, you can always sell the 741 with gears, and keep or sell the sure grip or locker unit separately as they interchange between 741, 742, & 489 cases, the only part that doesn't interchange is the pinion
 
Backtobasics said:
On one hand it sounds like you are going to have this case for a long time, as you want to build it strong enough to support the larger motor down the road. On the other hand, you are concerned about resale value. These seem to contradict each other. If you have the 741 that you can build for the number you have in your plans, and you are going to run it for a long time, why concern with resale value?

Not attacking, just asking.
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Valid question.

Basically, I like to always try and have my cake and eat it too....LOL

Assuming the 3.55 setup works the way I hope (upgrading from 2.76, so looking for some more oomph) I wont be selling it or even pulling it out again as far as I am concerned.

But for the kind of money we are talking, I want to be sure I can get it back out of "whatever" if I can, or at least a good part of it, if I ever had to.

Spending $800 to do 3.55s and a surgrip (installed) in my 741 I am pretty sure I wont get back should it come to that. No one wants the 741, it seems, even though by rites it may be a fine unit.

Spending the same money or more on a 742 or 489? WIth 3.55s? It'll sell fast for a decent amount given what I have been watching online. Plus I get the theoretical "more beefiness" and bragging rights...LOL

I dunno.

In the end, I am just trying to save money where I can but still have what I want. 8)

That said, I have emailed Dr Diff and told him its a go....just waiting to hear back on a couple details and pay the man.
 
listen. EVEN IF YOU SPEND THE 1200 OR WHATEVER IT WAS ON THE BEST ONE YOU CAN/COULD BUILD OR BUY IT PRE-BUILT, YOU WILL NEVER GET WHAT YOU PAID FOR IT. IF YOU PAID 1200.00 FOR IT, ONCE IT IS USED, YOU WILL BE LUCKY TO GET 650.00 FOR IT ANYWAY. EVEN IF YOU USE IT ONE TIME. POINT BLANK
 
All I know is Rumblefish, Crackedback and others got me pointed in the right direction with my 741 CENTER SECTION selection to go behind my mostly stock 340, automatic build......
 
personally i thing the 741,742, and 489 crap is just that. crap. i had a 741 behind a 440 for years. i believe there is a 741 in my dart too. launched it hard enough to get a couple inches of air under the tire numerous times and have never hurt it. but if you insist on a 489 then you have two choices. pay a cheaper amount for a used set that may or may noy not be set up properly or just spend the money for one that is guaranteed to be right. and i think i would go trutrac over a clutch pac if starting from scratch... nothing about this hobby is cheap. just something we all have to come to terms with.

http://www.eaton.com/EatonCom/Produ...ducts/Differentials/DetroitTruetrac/index.htm



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Shoot, i got a cone type 741 behind my mild 340 4 speed. I have had it on the road for a little over 2 weeks, and have dumped that clutch at 5 grand over 200 times.lol its holding greaaaaaaaaaaaat!
 
If you want to save money,then continue your search.
Good deals are out there,and Cash is King !
Dont get so caught up in 741,742,489,or resale value.
Get more into being a Hot Rodder,instead of forking out a ridiculous sum of money to someone.Search this thing out,and steal one !! Barter,Barter,Barter !!
Swap meets,Craigslist,E-bay,Abodies,ect...
I traded a B&M stall for my last SureGrip chunk. Shoot I cant even tell you what case it is,because it doesnt matter. I slapped that puppy in my 360 car,and light that thing up on a regular basis ! Dont settle for the big buck vendor,deals are out there !
 
Thanks for all the feedback guys.

I dont know , maybe I am just too particular, but I have been searching bascically since I bought the car two years ago for what I want.

True, I have been more or less ignoring 741 chunks....but I dont recall ever seeing a 741 with the clutch sure grip and 3.55s for sale that wasnt either a) broken or b) priced way high

The facts of the matter is:

- I have nothing (not much) to "barter" with at this point...anyone want to trade a clutch suregrip and 3.55 gears for my autozone oem style master cylinder? LOL

- I dont have local friends with caches of mopar parts I can fenagle from them, and I have been watching the "for sale" sections here and elsewhere all along.....just cant get all the stars to align. Maybe I am just not resourceful enough.

- People selling USED clutch suregrips seem to want damn near what a new one runs, at least at the swap meets I have been to...and theirs would still need rebuilt. The fact that the NEW clutch type suregrips are nationally out of stock right now tells you that they are hot items.

- USED chunks...whether 742 or 489...seem to be very pricey....again, at the swap meets I go to. And they will need rebuilt and the correct gears put in, or a sure grip put in, or both etc. I wont rebuild it on my own...would have a local shop do it, so there is a cost there. And by the time that math is done, its approaching the cost of buying a "new" one outright.

As far as the 741/742/489 debate......some say it matters, some say not.

I don't doubt those here who say they have abused their 741 cases behind high HP engines and had no issues.

But I also cant discount the stories I have seen from people saying the opposite.

Would the 741 "work" for my current setup?

Perhaps. It has so far.....

But the math STILL comes into play.

If I am going to sink money into a suregrip and gears for a 741, might as well spend an extra $100 and get the case that seems to be (at least from a technical standpoint) heavier duty.

The case REALLY isnt the issue here...it is finding what I want USED and CHEAP.

I have been searching craigslist and ebay, and have been going to car parts swap meets all this time.....I held out til carlisle last summer and found NOTHING that made sense for my needs.

Resale isnt a big worry of mine either.....but judging by what I have seen used chunks selling for, the combo I am buying will sell quick and get more $$ than a built 741 will.

I plan on keeping the 741/open/2.76 and shaft I have now for a while so I can swap out for long highway trips if I need to....

In the meantime, I am pulling the trigger on the setup by Dr. Diff......the sting of the spend should go away once I get it installed and tromp on the go pedal....LOL.....and there is no doubt that it will be strong enough for anything I will end up throwing at it and whatever abuse I give it.
 
Here is how I do the math.

Using your 741 case 3.55 sure grip will cost you about $800 and IMO be worth at least $500 used in great condition. Your looking at about $300 depreciation and $550 less initial investment over the 489 new case.

The new 489 case with 3.55 sure grip will cost you $1350.00 and IMO be worth $750 used in great condition. Your looking at $600.00 depreciation and a much higher initial investment.

I have always been the same wanting the best parts money can buy. Guess the age and economy are taking there toll on me. Now I'm just happy to have a car I can get in and drive.

On a side note I was just working on a dana 60 out of my Dart that the previous owner put in. That thing is monster overkill! Guess I'm ready for a Hemi 4 speed when the time is right.
 
You need to look harder.

I've seen 741 open chunks with 3.55 gear for sale for under $150 many times. Buy a clutch SG unit $150-200 and spend $75 on a clutch pack, install it with fresh bearings and go. Under or right at $500.

A friend picked up 4 or 5 chunks, mostly 741's, one or two 489's with 3.55, 3.91 and 4.10 gears for $125 each. They were listed on craigslist and sat unsold for almost 3 weeks.

If you don't do the legwork you'll pay a premium for convenience because someone else did the work.

I had a 741, 3.55, rebuilt cone sure grip unit for sale here for $450 and got NOT ONE response. I put it on the shelf and decided to use it in a project.
 
I agree. Keep looking for the right one at the right price. A lot of sellers have $$ signs in thier eyes.Barret Jackson fever has almost ruined this hobby for entry level folks,but now the economy has brought a more realistic pricing field. You should be able to find a reasonably priced chunk without having to buy 5. Not everyone is drunk on BJ fever.
 
Yeah the chunks my friend bought were not reduced in price for volume, the guy wanted $125 each for the open sets. You could have bought 1 for $125.
 
I don,t see a problem getting a Cone-type suregrip,they were put in many a Mopars.Both types wear out in time.:clock:I,ve seen many of both cone and clutch-type for sale here in the $4-500 range.I also don,t see the need for the 1350 yoke,unless your racing a 8-10 sec car.JMO
 
I would not be afraid to use the 741, I have yet to see a broken one. In fact the only 8 3/4's I have ever seen destroyed were ran low on oil or were open units with worn out spyder gears that lost teeth. All limited slip units will need a rebuild eventualy. If you have to have a 489 check craigslist, alot of people just list 8 3/4 chunk or pig. Alot of 2.76 open 489's out there. Last one I got was $75. They are heavy and shipping is the killer. I dont know what your plans are for your car but for a car but unless your planning on racing it seriously all the time I think the 489 is probably not going to make any difference.
 
I built my own 8 3/4, it's not that difficult if you research it and pay attention. I purchased a rear with a 489 chunk 2.76 open. I then bought a used clutch type sure grip and rebuilt that, new gears (3.55) and all new bearings, seals etc. I took my time and shopped around. I also fabricated my own back brace. I have just a shade over 6 bills in mine, complete rearend ready to install.
 
I see you're in Pa. There was a 2.79 clutch suregrip center section in Altoona for $100 or $150 last summer. Watch the Traders Guide. I just picked up a 489 case 3.55 cone suregrip for $300 Tues. Saw it on Pennswoods and turns out he is a member here. Thanks Big Don!
There are deals out there, just have to keep looking. You can look at the Traders Guide online if you don't want to buy it every week. Pennswoods.net/classifieds lots of deals on there.
 
kork340 said:
I see you're in Pa. There was a 2.79 clutch suregrip center section in Altoona for $100 or $150 last summer. Watch the Traders Guide. I just picked up a 489 case 3.55 cone suregrip for $300 Tues. Saw it on Pennswoods and turns out he is a member here. Thanks Big Don!
There are deals out there, just have to keep looking. You can look at the Traders Guide online if you don't want to buy it every week. Pennswoods.net/classifieds lots of deals on there.
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I know there are deals out there...but I swear i have been watching for a long time and nothing seemed to work.

$300 is good, except I dont want the cone type.

I pulled the trigger today and I should have my new chunk in a couple weeks. :thumblef: I hope the new gears make the difference I am hoping for.

Thanks everyone for your advice/comments. Lots of good points.
 
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