1. Mateya

    Mateya Active Member

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    Originally my 70 RR had a 383 which means that it has the 8 3/4 rear end. Now my car has a 440. I was wondering if anybody else has been in the same situation and what your approach was on your restoration. I did read through some of the other threads on here related to a 8 3/4. Here are a few of my initial questions:

    1) I am assuming that the 8 3/4 is sufficient for a 440? I am planning on enjoying my car when finished. Nothing crazy, no drag racing, etc.

    2) What is the general rule of thumb on rebuilding a 8 3/4 rear end when restoring? In other words what is the best approach to see if anything needs done to the rear end or not?

    3) If I want a good all around setup meaning if I want to cruise down the highway at 70 mph but also have nice acceleration should I change anything with the setup?

    If anybody has any additional information, thoughts, pictures, etc that would be great. Trying to learn as much as I can now before I get to this point in my restoration.
     
  2. RKNRLR

    RKNRLR Well-Known Member

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    I put a brace on mine when i rebuilt the engine. Got it from moser, about $70-80, welds right on. Stiffened it right up.
    Gonna put some 4:10's in shortly too.
     
  3. Russ69Runner

    Russ69Runner Well-Known Member

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    If you look back at some old thread's you can see. Have the 741 the lightest rear end in the production line. It had a 2to 74 ratio I think that is rite. It would be like dragging a weight down the road when leaving the stop sign. But bet it would top out at 150 on the highway. So went with the 3:55 gearing to get a little more ump off the line. Mine is going to be a driver not a race car but want a little something to show my friends I do have a muscle car. Now what differential do you have and bought my stuff from Mr Diff. He can steer you in the direction you want and is a good person to work with. Hope that in the future that I do not decide on putting a 5 speed transmission in. Only time will tell. I have the A833 four speed. Have heard different prows and cons on the subject. Just a few of my thought's on the subject. Russ.
     
  4. 69hemibeep

    69hemibeep Sponge Bob Square Wheels

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    8 3/4 + 440 + auto + street tires = :thumbsup:
    8 3/4 + 440 + auto + slicks = :praying:
    8 3/4 + 440 + 4spd + street tires = :):(
    8 3/4 + 440 + 4spd _ slicks + :rofl::rofl:
     
  5. ACME A12

    ACME A12 Plaid Sport Coat Wearing Moderator Staff Member

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    Good summary. Nailed it. :thumbsup2:
     
  6. 69hemibeep

    69hemibeep Sponge Bob Square Wheels

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    I like 323s, 355s will do what you want but a few more RPMs on the highway
     
    Ranger likes this.
  7. quikbird

    quikbird Well-Known Member

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    If it doesn't leak you can probably just clean it up and drive on down the road
     
  8. Russ69Runner

    Russ69Runner Well-Known Member

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    Don't tell me that. Well that means a cam is going in to give me a few more RPM'S Then. Their goes that gas millage!!!!!!
     
  9. TOMRR

    TOMRR Well-Known Member

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    I have in my 69RR 440hp 4-speed and 489 case 8 3/4 3:55 gears. 415 HP 475 Ft.lb TORQUE . NO PROBLEM. mine never seen the drag strip just street duty about 2000 miles a summer
     
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  10. 69hemibeep

    69hemibeep Sponge Bob Square Wheels

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    Tom that's why the smiling one is up there. You have the stronger gear set it depends on how you drive and if you rough it up some what kind of tires. BFGs for instance are so hard you will never hurt anything they just go up in smoke.
     
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  11. ACME A12

    ACME A12 Plaid Sport Coat Wearing Moderator Staff Member

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    If you're driving a RR with a big block do you REALLY give two shits about the gas mileage? These things are toys these days. Daily driver status for these cars went out the door about the time that George H.W. Bush took office...if not years before in most cases. The only thing that should be measured these days is smiles per gallon... :D
     
    TOMRR, Russ69Runner and Mateya like this.
  12. Russ69Runner

    Russ69Runner Well-Known Member

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    Think this runner will be a week end car or just a night on the town. We have Old Town in Kissimmee Fla. all the old car's go their. Then some guy's go too a sport's bar up town and some meet up at the Mall. Their is a Mopar club in Brandon but that is 75 miles from home. Well that is to far into the future but think about it keep's me working on the car. Russ. :thumbsup2:
     
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