im building a supercharged beast...need a strong rear for the car...cant figure out what my best route is...this is a street car and will see some occasional track time...it needs to be able to turn so no st8 drag rear ends...want to try and keep it affordable as well...suggestions?

 

12 bolt, dana 60, or ford 9".

http://www.spohn.net/shop/1982-1992-...dy/Drivetrain/

Maybe someone else can help you out a bit more

 

A differential that can take a lot of power and be affordable can't be used in the same paragraph.

Don't expect the tiny factory 10 bolt to last very long even if you do the common "beef up" modifications. A 9 bolt is a little bit stronger but not by much. If you can find the factory replacement Dana 44 for a cheap price, it's a strong diff however one in good condition can cost the same as an aftermarket diff as mentioned above.

Expect to pay at least $2000 for a good aftermarket diff. Just put a good posi in it to drive on the street.

 

I'm in 100% agreement with Stephen. The rear that is capable of that power level and being reliable is not cheap. Some things that will affect how hard your car will be on the rear are: Automatics are easier on the rear, unless you use a tranny brake to launch. Slicks will allow harder launches, and are harder on the rear. Of course, it depends on how you drive it too.

So an auto with no trans brake, with plain street tires, not being abused........you could get away with a cheaper rear end. But that is kind of a waste of 600hp.

 

i would go moser 12 bolt with a 3.73 gear and detroit locker or spool.. i would stay away from the detroit true trac.. i broke mine.. its pretty much a spool right now..

also, make sure the transmission is gonna hold too..

 

i have a tremec tko 600 trans...should hold...plus i plan on sending it to promotion to get stronger gears put in and there shifter set up supposedly fixes a lot of the probs the tko one has...i didnt mean cheap as in less then a grand lol...i just dont want to be coughing up like say 4-5 for a rear...yeah i was looking at either picking up a moser 12bolt or a 9" starting to push more towards the 9" though...with 33spline axles and 4.11 gears with a posi

 

There is no doubt that I would use a Moser 12 bolt if it was my car. The 12 bolt is lighter than the others and more than strong enough for 600 HP. I would upgrade to 33 spline axles and use the 9 inch Ford type housing ends to eliminate c clips. You can get this for about $2300 plus shipping.

 

x2 - if you wanted even more insurance, go to the strange s60. A 9" is no stronger than a 60, but takes more power to pull.

Our outlaw 10.5 car is currently still on a 12-bolt. 40 spline axles and a spool with pro gears, but just a 12-bolt. With the na 468(750-800hp range) I'm cutting mid 1.2 60's and high 5's in the 1/8, we've previously been 1.1x 60's and 5.0's on this same rear, has been in the car for 5+ years now. I'll either break it and/or swap to an S60 when we put the blower motor in.

 

thx for the info i think ill go with a moser or strange 12 bolt then since its lighter...

 

I'm going With the Strange 12 bolt with 4.11's from Spohn sometime in the Fall, becasue it is lighter, and slightly less expensive. This post helped me alot, thanks.

 

I am going with Quick Performance and getting a ford 9" with 35 spline axles.

All total it will be about $2000usd.

The amount of weight difference from a ford 9" to a moser 12 bolt is about 30lbs.
If you want to be in the 10's or high 9's, go with the 9", it'll take more power in the long run.

The moser 12 bolt will hold 600hp, but think to the future if someday you'll have more HP, you'll be happy to have the 9".

 

pshhhhhh! my 7.5" 9 bolt can handle 800hp! i welded the axles together in the pumpkin and threw trans fluid in it

lol jk
im gona be close u to. something like 480hp on motor and a 100-150shot. i tho dont have ur budget so i was gona try and get a ford 8.8 to fit. alot more work but i should get it in for less than 500. and be close to the strength of the 12bolt if not alil more.

if your gona be putting out more than 600hp in the future u would prob be better off with the 9" or dana. 12 bolts arent a bad rear... but u can break them. 9" would be bullet proof same as the dana or u could get that new MOSER FAB 9 rear. looks sick.

 

i have a 9'' in mine and love it with detroit locker and 33 spline but if you wanted to change gears it's easier cause the gears all come out as a unit so its easier to set up

 

Are you sure you have a 33 spline locker? I have never seen one. All that I know of are 28, 31 and 35 spline Detroit Lockers.

 

stay away from strange rear ends. I had purchased mine last year and it made a huge whine. I had to then take it to a strange dealer 150 miles away. Then replaced the gear set with a crappy not correct gear set. It then made more noise than i could handle. I had to wear ear plugs to drive it, then I took it back the next day. They sent it into strange again, they said they put another gear set in, but told me since I have welded on lcarbs, that that would cause the loud amount of noise and that they will not cover it again! I was so pissed, they even told me that I should of bought a moser, horrible customer service and I will never do business with again!!!!

 

well JoeBlue83, Thanks for the Huge heads up. What did you end up doing? go with Moser?

 

I can't afford another one, I am just going to keep the one I have and try to fix it myself.

 

Joe, let me know if you need any help with that.

 

Well, when I get my Moser, I'll let you know if it whines to, lol. Should Be getting it within the next 2 monthes

 

I agree with this, I would rather have the 9 inch due to ease of working on, price of parts, and HUGE aftermarket support, the 12 bolt is a fine rear end, but if you are going to use 9 inch housing ends why not use the whole thing?

 

Moser 12 for me, it might whine, but I cant hear it over the exhaust. Works so far

 

The 12 bolt has just as much after market support as the 9 inch. The 12 bolt is more than able to handle 600 HP and it's cheaper. The 9 inch doesn't have a good strong clutch type limited slip differential. The 12 bolt has the Eaton, which is far better than the Ford Traction Lock. The 12 bolt is lighter and uses less power to turn. I have owned my rear end shop for about 12 years now and I don't think the 9 inch is any easier to work on than the 12 bolt. I have a 9 inch in my car, but if I was doing it all over again I wouldn't put another one in it.

 

What kind of gear Ratios would you suggest for about 500-600 hp, focused on top speed a little more than Acceloration, Gear Head? 4.11 always sounded nice to me, but, I'm not sure that's what I need...

 

I'm no expert on gear ratios. There are some computer programs out there that can help with that. There are so many factors that play a part in the correct gear ratio and I can't guess at it and tell you what you need.

 

4:11's are based for quicker acceration. You would be better off with 3:73's IMO

 

Alrighty, thanks for the Suggestions. Yeah, it was a toss up between 4.11's or 3.73's, somewhere in that range...

 

go for something in the 3.9 range, I did!

 

My old 83 had a little over 400 at the wheels and a 200-250 plate and I went through like 3 700r4 and 1 th350 before my 10 bolt gave me a issue but if it would have hooked up better it would of before the first 700r4. I personally like the 12bolt over the 9" because I have installed a couple 9" in other cars and I actually blew 2 of them on a 68 ford truck with a 460 10.5:1 comp and dual quad and some juice (no dyno runs so your guess is as good as mine).

 

Whats funny is right after I posted my last post, I went to Spohn, and found that they have a 3.91, so, That's what I'll get. lol Thanks for all the help guys

 

I agree that the 12 bolt is a good rear end, and maybe after working on them for 12 years it is easier to work on, but for me it is a huge benifit to be able to remove the pig to work on it.

As far as the posi differentials, who in the world uses a ford traction lock with 600 hp? I would want a real high quality differential in either rear end if I was going to put 600 hp with it.

I also do not like the way the tourqe arm attaches to the 12 bolt, with all the tourqe put thruogh that part of the housing I believe it could throw your ring gear contact off, but I am no rear end guru, you will know more about that than me.

I am not trying to talk anybody out of a 12 bolt, it is a great rearend, I just wanted to give some input on why I would choose a 9 inch over a 12bolt, but everyone has a right to there own opinion.

 

Yes, it is just my opinion about the 12 bolt, and I respect your opinion about the 9 inch. It is my belief that the 12 bolt is better for anything that is street driven and raced from time to time. The 9 inch would be better for something that makes over 700 HP and is raced often. Again, that is my opinion. I don't feel the same way about a Chevy 12 bolt. The OEM housings are not as strong as the Moser housings. I don't think a OEM housing would be good for much over 500 HP. The Moser housing is much stronger than the OEM housings.

 

I apreciate the very educated and polite response, and I agree with you about the moser vs. gm housings.

 

you guys ought to check out some of the roundy rounder mags. a friend bougt a 9in houseing & axels for $700. 3rd member (gear/posi) $600. used his old brakes.

 

define 'Roundy Round Mags' and where we might come across such a Wonderous document, please?

 

i might have jumped the shark here. i got to thinking those $ are 4 or 5 years old. but go ahead and look at circle track & raceing tech mag. when we ran the modified (when i was in high school) i was supprised at how much more exspecive drag race parts were than stock car stuff. try quick performancr or danny miller rear gear. there are others........oh yeah, look at wall mart for the mag. or on line at peterson publishing.

 

I'll keep an Eye out for it, Thanks Brother.