Author Topic: High HP Stroker & 4 Speed: 8 3/4 or Dana Rear?  (Read 1565 times)

Offline Road_Runner

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High HP Stroker & 4 Speed: 8 3/4 or Dana Rear?
« on: October 26, 2010 - 08:28:14 PM »
I know some folks run a lot of HP with 8 3/4 rear ends, but Mopar put Dana's behind 440s & Hemis for a reason.  How high is too high horse power-wise when paired with a 4 speed and an 8 3/4 rear?   Is 550 - 600 HP too much or can the 8 3/4 be beefed up to handle the extra HP & torque as well as a Dana?  I've seen some ugly pictures & video of cars losing an axle and/or breaking the rear during a hard launch.  It usually ends up with the car & the wall trying to occupy the same space.  Anyone here street/strip a high HP/manual/8 3/4 combination?  This will be in a 70 B Body car, full interior, etc.  Opinions? 

Thanks, Jim
1970 383 Roadrunner Tor Red
1973 318 Barracuda Mist Green
2014 Mustang GT/CS Convertible All Black




Offline Chryco Psycho

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Re: High HP Stroker & 4 Speed: 8 3/4 or Dana Rear?
« Reply #1 on: October 27, 2010 - 12:19:10 AM »
as long as the tires spin you will not hurt the diff , that being said if you are going to spend to upgrade the 8 3/4 just buy a dana & be done with it

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Offline challenger500

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Re: High HP Stroker & 4 Speed: 8 3/4 or Dana Rear?
« Reply #2 on: October 27, 2010 - 02:50:28 PM »
I had 500" paired with non-Hemi 4-sp. 6 years, no problems whatsoever.. but as chryco mentioned "as far as the tires work as rubber band" no problems  :biggrin: equals to ****ty 60ft times if that's what you're looking for. For regular street you're not gonna get grip anyways.

but, don't go centerforce path... mine after tear down, works but definitely had some beating
http://sphotos.ak.fbcdn.net/hphotos-ak-snc3/hs601.snc3/31661_121339534573644_100000927930724_107119_479630_n.jpg

http://sphotos.ak.fbcdn.net/hphotos-ak-ash1/hs541.ash1/31661_121339544573643_100000927930724_107120_3071013_n.jpg
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Offline Road_Runner

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Re: High HP Stroker & 4 Speed: 8 3/4 or Dana Rear?
« Reply #3 on: October 28, 2010 - 07:31:37 AM »
I had 500" paired with non-Hemi 4-sp. 6 years, no problems whatsoever.. but as chryco mentioned "as far as the tires work as rubber band" no problems  :biggrin: equals to ****ty 60ft times if that's what you're looking for. For regular street you're not gonna get grip anyways.

but, don't go centerforce path... mine after tear down, works but definitely had some beating
http://sphotos.ak.fbcdn.net/hphotos-ak-snc3/hs601.snc3/31661_121339534573644_100000927930724_107119_479630_n.jpg

http://sphotos.ak.fbcdn.net/hphotos-ak-ash1/hs541.ash1/31661_121339544573643_100000927930724_107120_3071013_n.jpg


I've actually got a 70 23 spline 833 out of a 383 Challenger RT I've had in the garage for 20+ years myself.  If I go with a gear splitter type 'add on' overdrive I'd like to use it.  Or I'll go with Passon Performance's 4 or soon to be released 5 speed 18 spline overdrives depending on what the cost is when its announced.  I can see things are pretty torn up with the Centerforce clutch but what is the lesson here?  Are their clutches bad, not suitable for street use, what?  And what would you recommend instead?  Right now the RR has Goodyear street radials, but I would consider DOT cheater slicks on back to get more traction on the street.  Is that going to stress the 'rubber band' too much?

Thanks, Jim
1970 383 Roadrunner Tor Red
1973 318 Barracuda Mist Green
2014 Mustang GT/CS Convertible All Black

Offline Chryco Psycho

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Re: High HP Stroker & 4 Speed: 8 3/4 or Dana Rear?
« Reply #4 on: October 28, 2010 - 01:58:04 PM »
Cforce are all hype & advertizing , the product is expensive & poor quality
I use McLeod for clutches,, less $$ & top notch product
for Dot street slicks you will be ok , they do grip better but will still spin , no way you will lit the front wheels with them without ladderbars

Challenger - You`ll wish You Hadn`t

Offline inviolet

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Re: High HP Stroker & 4 Speed: 8 3/4 or Dana Rear?
« Reply #5 on: October 28, 2010 - 03:19:58 PM »
What gears are you looking to run? Dana selection differs a little for 8 3/4. I'm trying to get an idea for my situation.
« Last Edit: October 28, 2010 - 03:25:36 PM by inviolet »

Offline challenger500

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Re: High HP Stroker & 4 Speed: 8 3/4 or Dana Rear?
« Reply #6 on: October 28, 2010 - 04:36:53 PM »
Well, for normal street CF , nothing to complain.
But after few passes on prepped track, even though with dot legal street soft compound i.e. well spinning through 1rst and some 2nd, I found that the clutch operation changed. Dramatically, No, noticeably, yes. After that, normal street driving ok but didn't do the track anymore.

So it really depends on the wish list. I did like the light pedal operation with the CF though
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Offline Road_Runner

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Re: High HP Stroker & 4 Speed: 8 3/4 or Dana Rear?
« Reply #7 on: November 02, 2010 - 12:41:38 PM »
Cforce are all hype & advertizing , the product is expensive & poor quality
I use McLeod for clutches,, less $$ & top notch product
for Dot street slicks you will be ok , they do grip better but will still spin , no way you will lit the front wheels with them without ladderbars

Thanks once again for the advice, I'll definitely go the McLeod clutch route whichever trans I use and am leaning to keeping the 8 3/4 since it came in the car.

Later, Jim
1970 383 Roadrunner Tor Red
1973 318 Barracuda Mist Green
2014 Mustang GT/CS Convertible All Black

Offline Road_Runner

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Re: High HP Stroker & 4 Speed: 8 3/4 or Dana Rear?
« Reply #8 on: November 02, 2010 - 12:52:30 PM »
What gears are you looking to run? Dana selection differs a little for 8 3/4. I'm trying to get an idea for my situation.

You're right, the ratios differ a little but not much really.  8 3/4's have a 3.55 gear, its 3.54 in a Dana.  I'm not sure about availability of all the different ratios that used to be available, but you should be able to get in the ball park ratio-wise with either rear.  I've run 3.23, 3.91 & 4.10 gears myself in B bodies and for little to no highway driviing you can go with the 4.10 and do OK around town.  Want to go down the highway for a few hours to go to the track or a show?  You're going to hate that steep of a gear.  That's why I definitely plan on running some kind of overdrive on the Roadrunner so I can go with a 4.10 in either an 8 3/4 or Dana 60 rear.  With a decent O/D the final ratio is around 3.0 to 3.2 which is close to the 3.23 which most of these cars came with from the factory.  I rode shotgun in a 69 Superbee that pegged the speedo at 155+ with a 3.23 rear gear so I know these don't limit top end at all!!

Later, Jim
1970 383 Roadrunner Tor Red
1973 318 Barracuda Mist Green
2014 Mustang GT/CS Convertible All Black