Fat Blocks and Rear Ends

[vidman]

I was just curious to what rear ends you guys are using behind all that power. I have a pretty stout 504 with a modified th400 and was certain that the stock 12 bolt would not work for long. been kicking around a custom built 9" style or dana 60. I will be using some big fat tires to get it to hook up.just looking for ideas that have worked for all that power..Thanks for the help

[Super73]

What do you think you will make power wise?

I am currently running a truck 12 bolt with 4.56 gears moser axles and an Auburn posi. Now with that said, I have a 9" sitting waiting to be built.
Posted via Mobile Device

[vidman]

Engine builder is shooting for 650 ft lbs abd 575 hp. I told him i was more interested in the tq numbers. The truck will see no track time, just some weekend street pounding. The cam and heads will run out of steam at 6200. just building it as a street thumper

[GASoline71]

If you're not hooking it every weekend at a track, I'd say the 12 bolt will live a good life with welded tubes, an upgraded posi, and aftermarket axles. Might wanna look at upgrading the yokes and ujoints to accept a joint larger than a 1310.

Gary

[vidman]

If I do not change the axle assembly I was planning to do the 1350 joints, A good posi unit and some Moser or Mark Williams axle shafts. I just don,t like things that break. It will most likely never see the track

[BigDan3131]

I noticed its a 4 wheel drive, is it still that way or did you remove the front axle for 2wd stuff? If you plan any off roading I would switch out both front and rear axles to a 14 bolt front and a Dana 60 or 70 rear.

[RockTonka]

Kinda doing the same thing you are (but with less power)...the 12B didn't last in mine (blew out the center pin...walked into the pinion).
Went with a narrowed D60, big bearing F*#D ends, 35 spline Mosers, Powerlok, discs...no track time, just don't like things to break and didn't want to have to do it over.

[djracer]

Buy a nine inch!
Posted via Mobile Device

[vidman]

Originally Posted by BigDan3131

I noticed its a 4 wheel drive, is it still that way or did you remove the front axle for 2wd stuff? If you plan any off roading I would switch out both front and rear axles to a 14 bolt front and a Dana 60 or 70 rear.

Its not a 4 wheel drive. My DD and my willys is.. I have no problems having a custom axle built. I think if i go that way, It will be either a 9" or the Dana 60 I hate to put the money in the 12 and still blow it up when I,m 50 miles from home..

[vidman]

Originally Posted by RockTonka

Kinda doing the same thing you are (but with less power)...the 12B didn't last in mine (blew out the center pin...walked into the pinion).
Went with a narrowed D60, big bearing F*#D ends, 35 spline Mosers, Powerlok, discs...no track time, just don't like things to break and didn't want to have to do it over.

Nice looking 60 RockTonka. what size tires are you running and how much power you got.

[Marv D]

If your gonna use street tires,,, you will unlikely hurt parts with the clouds of tiresmoke your going to create

[vidman]

Once i figure out what to use out back then I will have to make it hook up. Already cut my bed and tubbed my wheelhouses. Thats what I like a lot of smoke and noise...........But no parts breakage

[skeeterbug]

Personally if it were just for street/strip use, with street tires, i would just keep the 12 with minimal upgrades and use my funds elsewhere. Strip occasionally, even with 10 or 11.5 et streets, street gears ie 3.73, and stock suspension prob last a good while mabey forever? BUT... I wouldnt try beating on it with listed components then one day decide to go Big tire (31x18.5), 5.14 gears, and good drag suspension setup ect., on same 12 bolt expecting it to surive. Ask Me How I Know, been there, done that, and got the sh#@ on the ground to prove it.

[skeeterbug]

[skeeterbug]

In my case im going 9" via '71 Ranchero,5.14,spool,big bearings, and 35 splines all MOSER and not gonna look back!

[vidman]

I plan to run at least a 14 to 16 inch tire so it will hook up. but no track time. It,s funny because i have broken a lot more parts on the street than on the track. I would to hate to drop a grand into the 12. It,s stock with open diff and 3.73, so i figured I would do the custom built 9" or the 60. I have a lot of coin in the motor and trans and would,t want to cheap out on the diff.. Sorry about all those busted teeth. been there

[skeeterbug]

Thats alright, l knew something was gonna have to give just didn't expect it so early in the season. It kinda caught me off guard, first pass of test n tune with the new setup and didn't even get to the 60' beam. All I saw was hook, spin,hook and the drive shaft went thump thump before I could get off the loud pedal. Oh well, its on like donkey kong next weekend l will be back together by then.

[vidman]

Good luck with the fix and thanks for the help

[69GMC910]

I had this 12 built, and should handle more than I'll ever throw at it. Welded tubes, big bearings, 3.42's and an Eaton. Built by Tom Rockwell Racecars.
Posted via Mobile Device
Posted via Mobile Device

[69GMC910]

Posted via Mobile Device
Posted via Mobile Device

[69GMC910]

Posted via Mobile Device

[Marv D]

Ohhh if were gonna play show and tell

lol
I don't think you'd break this,, it's surviving 790horse, 1.2x sixty's in a 3000 pound chassis, tansbrake, wheels up launch and tripping the 60' timers with the rear tires


It's only

On the more mild (and affordable side of the 9"
I've beat on the 9" in my 66 with 666HP, big slicks, Iron aftermarket centersection, Richmond street gears, Dyneer No-spin locker. No failures yet with 3650pounds, 1.4x sixtys on a transbrake launch. EXCEPT axle,, 2 Strange 35spline axles, and one Dutchmans axle, now I'm running Mark Williams axles in everything and (knock on wood) I can't seem to tear them up.... waiting for the next weaker link to surface.

There are a lot of 9" haters out there and the little extra HP it takes because of the pinion placement, all sorts of technical excusses to not use a 9", BUT the fact remains the 9" has become the 'SOP' for hotrodders and racers. Parts are more plentiful and engineered / re-ingineered and re-re-re engineered that the 60 or so years they have been around they are about as bulletproof as anything out there,, and cheaper than anything else to build. (With 'cheap' being a relative term obviously).

The 9" is has become like the Miscrosot of rear ends... just about EVERYBODY carries a program for them,, and just about every parts house has the pieces to put one back together if something fails. The aftermarket proliferation of quality ad affordable pieces make the 9" a no brainer IMPO if your starting from scratch. Pick a wheel, then have the rear built to fit.

You get what you pay for,,, anywhere from around $1300 to $3800 depending on internals, brakes, bracketry, axles.. bla bla bla




BTW, keep in mind not all "14 - 16" tires" are created eaqual. I owned a set of MT Sportsmans once. A little 380HP 355 would blacktrack to 1/2 track with a best of 2.15 sixty foot times. A change to a Hoosier QT street tire was good for nearly 1/2 a second to the 60'. Hard as nails 'built fore looks' street tires just aren't going to hook and hurt parts. Changing from the MT Sportsman to the Hoosier QT was good for 3 axles, 2 u-joints, a driveshaft........... It's a very slippery slope

[skeeterbug]

wow, thats a mighty fine lookin 12 you got there, looks good and strong.

[69GMC910]

Thank you, I can't wait to abuse it!
Posted via Mobile Device

[vidman]

Originally Posted by 69GMC910

Posted via Mobile Device

I would wonder how a clutch type limited slip would work for any length of time behind some 600 plus motors and by the way , It sure does look perdy