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8.75 rear end with 440 4 speed?

street only street tires U will be fine
think about your
pinion snubber
good dana spicer U joints
drive shaft loop
frame connectors
even with any rear end
do not run a stiff hitting clutch
I ran a Borg and Beck/ Long from McLeod with soft springs and more counterweight
but there are other options
check your pinion angle too far off breaks parts
 
And NO side stepping the clutch pedal....unless you like broken parts.
 
no side stepping is why I use a light clutch
other people drive my car
even when racing we did not use a on/off clutch
you can break anything
 
For what it's worth, there was a 440 car around here with an 8 3/4 and a 4 spd, and it was on the build sheet that way.
 
IRRC, you could get a 440 4 speed 4 bbl and an 8 3/4 but if you got the 6 pack with a stick, it came with a Dana. Same thing with a Hemi stick but you could get the 8 3/4 if the Hemi was an auto.
 
I had a 64 Plymouth with a Stage III 426 Wedge, 4 speed w/ 8 3/4" rear & 4.10 Detroit locker. First the U joints went, then the clutch, then I twisted the driveshaft but I never had an issue with the 8 3/4" rear end. I also had a 68 RoadRunner with a built up 383, hemi 4 speed w/ 8 3/4" rear and various ratio gears depending on what I was doing. Never a rear end issue. Mostly street racing though as both cars got me kicked off the track for no roll cages for running too fast. Street racing is where I made my money. I set up a window washer in the trunk with tire compound to spray the tires when needed. That was back in the late 60's, early 70's, fun times. My 68 383 would eat up and spit out 440's including six packs so unless your 440 is really built, I wouldn't worry about it. My only real races were Hemi's and SS 454's and those I could often beat in the 1/8 but not the 1/4 mile.
 
Hemi cars were 4sp = Dana and auto was 8 3/4. If you have a Dana non-Hemi it was common refereed to as a drag pak car later on. BB 4sp doesn't always get a Dana. Early A bodies as well - 4sp didn't get you a 8 3/4 either always.
 
buddy has a blown 440 with a 4-speed in his '55 Dodge truck - had 18" wide mickeys on it with an 8 3/4... he drove that thing hard without any issues... swapped in a blown hemi and finally grenaded the rear with 1100+hp.... I think you'll be fine
 
First hard launch with my 64 Polara 500 Ramcharger Auto with a freshly built 440 and broken the 8-3/4. The rear lived with the 426 Wedge until the engine puffed and we put the 440 in the car. Switched to a Dana 60 and the fastest the car ran was 10.96 in the 1/4. Run an 8-3/4 until or if it breaks then worry about.
 
Cranky said:
IRRC, you could get a 440 4 speed 4 bbl and an 8 3/4 but if you got the 6 pack with a stick, it came with a Dana. Same thing with a Hemi stick but you could get the 8 3/4 if the Hemi was an auto.
Click to expand...
This is good to know. Thank you
 
I beat a lot of 8 3/4s over the years.
The 65 Fury in my pic had a 509 cammed 440 and 26" slicks.
The 8 3/4 never broke with power shifts and holeshots at 3900 lbs.
You can break it if you try, you'll be fine.
PS leaf spring flex without a snubber would probably destroy a U joint though.
 
8 3/4 w/o slicks usually live a long life. Can you break one? sure. Just like 23 spline 4 speed. Can you brake them?, yup. But it has been my experience on the street both live pretty well under hard abuse. And I do beat on em.
Doug
 
Seems to be a guy named Jeff thinks side stepping a clutch is good. Ok....go for it man! :D
 
Last edited:
MAX has lived with his 8 3/4 for 57 years so I'm guessing it's OK. I don't know what gears Fred, the original owner, was running when he was fighting the street wars, But, when I got him he had 4.88s and I had them changed out for 4.11s. The housing still had the factory axle seals!
 
dvw said:
8 3/4 w/o slicks usually live a long life. Can you break one? sure. Just like 23 spline 4 speed. Can you brake them?, yup. But it has been my experience on the street both live pretty well under hard abuse. And I do beat on em.
Doug
Click to expand...

All right then - that's was the straw that broke the camels back - SLICKS. I did a lot of hard beating on the 8-3/4 it lived but it was probably giving up the ghost before the 440. The first run with the 440 was at the track with SLICKS. We can break anything. Just give us a chance.
 
tenfive0 said:
All right then - that's was the straw that broke the camels back - SLICKS. I did a lot of hard beating on the 8-3/4 it lived but it was probably giving up the ghost before the 440. The first run with the 440 was at the track with SLICKS. We can break anything. Just give us a chance.
Click to expand...
Heavy car, high rpm launches with sticky tires.....usually isn't a good mix. Launching at 6k with a 3400 lb car killed a couple once the car got into the low 11's.....
 
Cranky said:
Seems to be a guy named Jeff thinks side stepping a clutch is good. Ok....go for it man! :D
Click to expand...

Everybody is concerned with the rear end, Dana 60 vs Mopar 8 3/4" but the SMALLEST diameter component in the 4 speed drive train is.....the input shaft to the transmission....albeit the 18 spline shaft or the 23 spline shaft. During a "side step the clutch" or a bonsai start, this shaft is subjected to the full torque produced by the engine at, say a 5000 RPM start, with the transmission shaft at ZERO rpm, neglecting 10% (or less) clutch slippage, this shaft will twist several degrees. After several impact twists, it will likely fail, probably right behind the clutch splines at the spline's root diameter (smallest x section). I'd be more worried about the transmission rather than the rear end setup. Just my opinion of course.
BOB RENTON
 
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