Okay so I have a 69 dart 225 /6. I am thinking that in the future I am going to put some power in it so I would like a nice platform to build on.
I'm starting with upgrading the rear end.
I've already done some other upgrades such as breaks, gas tank, spark plugs, etc. all maintenance/necessary upgrades so it's drivable now.
I'm planning on getting an 8 3/4 rear end as of now. I have a little over a grand set back for it now. So my question is where is the best place to get the rear and what gear ratio should I get.
Right now i have very few/mild performance upgrades. 2bbl carb. New plugs and wires. Electronic ignition. And very soon exhaust. Basically stock power. But in the future I am planning 300+hp. I would like a gear good for both set ups. This is also a daily driver. I was thinking 3.23s. My tires are slightly taller than stock in the rear about 27 inches. I was just wondering if that gear is good enough to possibly chirp a tire and get off the line but also keep the revs low on the highway and get decent gas mileage.

Thanks for the help

3.23 is a great choice. I suggest getting a "clutch type" sure grip limited slip, or if you have extra cash to get the TrueTrac type. Doctordiff.com is a great source for 8.75" axle parts and assemblies.

Best,

Lou

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Home of Slant6-powered fun machines since 1988

Thanks for the help Lou. I'll check it out

Spend some time with one of many on-line speed / RPM calculators, to get a better "feel" for the final drive RPMs each ratio will get you.

https://www.ringpinion.com/calculators/Calc_RPM.aspx

It is time to install a tachometer in the vehicle, if you do not currently have one.
DD

I really think the 3.23s will work. Now do you think it's possible to get a used 8 3/4 sure grip for $1000 or in that range. It doesn't need to be race ready or anything just good enough to hold 400 ft lbs of torque or so on a daily driver.

With that kind of budget you might consider an Explorer 8.8. You get Trac Loc and Discs, lower weight .....and change.

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Yeah....Im the one who destroyed this rare, vintage automobile.....

The explorer 8.8 sounds like a good idea. How much fab work is needed to drop in the rear end. And where can I find one.

+1. 8 3/4 rear ends are expensive and hard to find these days. Explorer rear ends are almost a bolt in and offer many benefits over the 8 3/4. Purity is the only reason to insist on the 8 3/4 axle. If I were in the market I would skip the vintage A body axles and go straight for the Explorer axle.

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Casually looking for a Clifford hyperpak intake for cheap.

Thanks for the help. Do you know if they make 3.23 gears for those rears. Bc I think I heard they come with 3.73s. And where is the best place to get one

You can get one in any wrecking yard,,,,they have a wide variety of ratios. from 3.23 to 4.11

They are not boltin. They need to be narrowed and they need new spring mounts welded on.

I paid:

$350 for a 3.55 ratio V8 rear end (Spauldings in Spokane)
$ 60 for a short side axle (Spauldings)
$100 to have the long side of the axle shortened and the new spring mounts welded (local machine shop)
$20 for new spring mounts (Summitt racing)

The whole shebang weighs 20 lbs more than a 7.25 (lots less than a 8.75)

They are 5x4.5 bolt pattern (8.75 is 5x4.25)

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Yeah....Im the one who destroyed this rare, vintage automobile.....

Okay thanks I think that's what I'll do.

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Yeah....Im the one who destroyed this rare, vintage automobile.....

Casey,
You could also look for a 8 1/4 out of a later A body and that would be a bolt in. Of course you need to shorten the driveline. You may want to get a plan together for doing the big bolt disc brake swap up front. It is a huge upgrade safety wise and then the 8.8 or an 8 1/4" would have the 4.5" bolt circle to match the front.

Rick

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2 Mopars come with Spark plug tubes. One is a world class, racing machine. The other is a 426 CI. boat anchor!

12.70 @ 104.6

The key word there being *almost*.

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Casually looking for a Clifford hyperpak intake for cheap.

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And just where did you get that info?
8.75 rears from an A-body are 5-on-4" pattern, and B-body rears are 5-on-4.5" pattern.

Roger