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Discussion Starter · #1 ·
hello all again....
i have the nomad with the leaky tank...anyway, i popped in a 383 stroker with a 700r4 tranny. the nomad came with a factory posi unit....i would like to put 411 gears in it to really smoke the tires....can anyone help me with what kind or size i need. i was on ebay, there are a bunch, but i already have garage full of "wrong " parts....
jeff
 

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If you're keeping the original axle housing they should be fairly easy to find.
Same "hogshead" was used from '55 thru '64. I've got a 3:73 that I replaced with a 3:50 to get better road mileage. With the o/d in that 700r4 the 3:73 or the 4:11 would be just about right. I would probably go with the 3:73 for hiway, I'm not building for power this time. (been there, done that). Anyway be careful to inspect very closely if buying used.
Also be sure to get a posi if you're planning to "smoke-em"
 

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I beleive "Tom's Differentials", "Randy's ring and Pinion" as well as Eaton and Strange sell the posi units or just the gearsets that fit the factory carrier. I currently run a F**d 9" with a Detroit Tru Trac posi and 3.89 gears. My small block can roast the tires easily. At freeway speeds with those gears, 28.5" tall rear tires and my 700R4, my tach reads 2250 rpm. With the 3.36 gears I had previously, the tires wouldn't "break" as easily however.....I could cuise the freeway at 75 mph at only 1900 rpm. There are on-line rpm calculators you can easily access that may help you make your final decision. Hope this helps.

Tom
 

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If you're going to put the 4:11 gears on the factory carrier you'll need to get a ring gear spacer along with the ring and pinion, the 4:-- gears are a different thickness and won't match with the pinion in the 3:-- carrier. I personally wouldn't use the factory carrier especiallly if it's not a posi, spider gears won't last under a lot of torque (been there, done that)
 

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Discussion Starter · #5 ·
papa,
i have the original posi rear end that id like to keep. i would like to put 4.11s to smoke em, and ive got the 700r4 to cruise hiway
jeff
 

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Discussion Starter · #6 ·
papa,
would you be interested in selling those 373 gears you pulled out if you still gotem? is there a big diff. between 373 and 411? I want to smoke em hard, but also would like to drive distances to go to the shows, would i need that spacer if i stayed with the 373? remember i have the factory posi rear end
jeff 57 nomad
 

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papa,
would you be interested in selling those 373 gears you pulled out if you still gotem? is there a big diff. between 373 and 411? I want to smoke em hard, but also would like to drive distances to go to the shows, would i need that spacer if i stayed with the 373? remember i have the factory posi rear end
jeff 57 nomad
the 3:73 that I have is the original hogshead complete, I'm not sure that the ring and pinion will work on the posi unit that you have. Do you know what gear posi you have.
 

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Discussion Starter · #9 ·
papa,
i have no idea what gears are in mine....on the pumpkin it has the p on it, and when i punch it, i leave two pretty black streaks on the ground.....is there a way to tell that is easy?
 

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papa,
i have no idea what gears are in mine....on the pumpkin it has the p on it, and when i punch it, i leave two pretty black streaks on the ground.....is there a way to tell that is easy?
I think you can jack the rear end up and turn one wheel. The other should turn if you have the original posi unit assuming it's working. Leaving two tire marks is a good sign. You can mark your driveshaft with a crayon while marking a wheel. Count the revolutions of the driveshaft with exactly one revolution of the wheel.

U can calculate your ratio if you know your speed, tire diameter, tranny final drive ratio etc. There are several free calculators for this on the internet.

PaPa should be able to help you.
 

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Discussion Starter · #11 ·
it is def. a posi, no doubt, i just want the higher gears..lower gears? to make it really rip the road. i have a 383 stroker with a 700r4, and i want it to move, if you know what i mean
jeff
 

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it is def. a posi, no doubt, i just want the higher gears..lower gears? to make it really rip the road. i have a 383 stroker with a 700r4, and i want it to move, if you know what i mean
jeff

It sounds as if you have enough power. If your engine isn't too powerful the 700R is a good drag tranny. The rear end should take up to 350-450 HP at the flywheel.

Traction becomes your limiting factor at that point. If you hook up hard a lot then I suspect you will eventually break either the tranny or the rear end.

If you are using street tires then you should slip enough to not break. If you hook up hard with slicks then something generally breaks after awhile.

You can move your springs in to get bigger tires. If you do then you will want to upgrade your stock rear or wait and see if something breaks. If and likely when something breaks you will probably know which direction you will want to go.

Driveline shock is harder on things than spinning tires. Have fun safely.
 

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Hey Jeff....go to Randy's Ring and Pinion web-site...they have a calculator. Or just type in "RPM calculator" on the internet and you should have a whole bunch of hit's. Hope this helps.

Tom
 

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Rear end size

I purchased my 4:11 from Reider Racing in Taylor, Michigan. They have competitive prices and are well know for there gears....If you need their number, you should be able to find them on the web, if not, let me know. Pete
 
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