8:75 peg style rear end,caseing*742

[birdistheword]

69roadrunner,440,auto,withbrake,weighs 3100lbs,650hp,on motor,300,on nitros,has 35 splines,spool,steelcaps,4:30 gears,14x32slicks will that rearend setup work?and how long?also with this combo will the car run 9:60,s thanks the Bird

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[JOHN SHERRED]

I LIKE THE 8 3/4 BUT IT SOUNDS LIKE YOU MIGHT BE BETTER OFF WITH A DANA 60 OR 9" FERD

I HAVE SEEN THE 8 3/4 HOLD UP TO A NITRO BURNNING HEMI AT 1800 LBS RUNNING 6.90

AND I ALSO KNOW OF 2 OLD SUPER GAS DUSTERS THE 8 3/4 SURVIVED WITH REGULAR INSPECTION AND MAINTNANCE

SET THINGS UP GOOD AND IT MAY BE FINE OR IT MIGHT DIE A QUICK DEATH

[BugEyedValiant]

Mopar just came out with a aluminum center section for the 8 3/4 that uses 742 gears. I emaailed mancini and they said that it is available and the cost is somewhere around $750. Dont know much else about it though.

[Leigh]

I would say find a buyer for the 8 3/4 that can use a good, solid setup like yours for an 11.00 and slower car. I can't see spending ANY money for that alum. case unless for a conversation piece. Sell it before it breaks and buy a Dana.

[RR69MOPAR]

8-3/4 don't like trans brakes.
It could live 100 runs or one run. When you break a rear end it usually takes trans with it.

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Cameron's Racing
69 Road Runner 426 ci wedge 9.69 @ 140
66 Belv 440 ci 10.76 @ 125
98 Dakota Pro Stock type truck (under construction)
79 Lil Red Experss Truck
96 2500 Ram 5.9
99 Durango 5.9

[Beeracuda]

Our 8 3/4 has 250 transbrake passes @ 2850lb and leaving at 5200. I just inspected it and it's back in the car for hopefully another year. It has the 4.86 pro gears with a 35 spline spool and stock caps.

I can't say how well it would hold up at 3100 lbs and that much horsepower, though. I can tell you that the street gears (like your 4.30's) we had in the car never made more than 100 passes! The last set we broke on the line also took out the yoke, driveshaft, track locator, bellhousing and the planetaries. We installed an Ultrabell, so we were able to salvage the case. But it was still a very expensive pass. If you are going to attempt it, I would check the gears regularly!

Monty

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Monty Brown
74 Barracuda
446 / PG
10.14 /134

[birdistheword]

Originally posted by RR69MOPAR:
8-3/4 don't like trans brakes.
It could live 100 runs or one run. When you break a rear end it usually takes trans with it.

whatbreaks first i use the steel main caps,35spline axles thanks the bird

[Beeracuda]

We've always broken the ring and pinion. Normally the pinion doesn't have much in the way of teeth left. We've never had any problems with the caps.

Monty

[birdistheword]

Originally posted by Beeracuda:
We've always broken the ring and pinion. Normally the pinion doesn't have much in the way of teeth left. We've never had any problems with the caps.

Monty

Beeracuda what gear ratio where you useing? also what do you think about the new 8:75 aluminium 742 caseing style peg? thanks the Bird

[440-8V]

Hey,I'm getting back to work on my 69 charger
and i'ts got the 489 case is it worse than the 472? I'm gonna run an automatic with a big block and 3000 stall no trans brake am I waiting for a granade at the track or what.

[birdistheword]

Originally posted by birdistheword:

Beeracuda what gear ratio where you useing? also what do you think about the new 8:75 aluminium 742 caseing style peg? thanks the Bird

you have been very luckie