8 3/4 or Dana

[moparcrazy]

Yup, they ain't cheap but good stuff usually isn't.

Yes totally Agree I have G.V Over Drive in my65 Satellite with 4:30 gears and 30" Tire, Race my car at the Track and on the Street it's Very Tame, Cruse @ 80 mph No Problem, about 3000 rpm

 

[dvw]

The overdrive trans is a maybe, more than likely its gonna be the mildly built 727 thats in it then a th400 whenever the 727 has had enough. I'm trying to gear it to about 150-155mph at the top of 3 third (not going to use lock up or overdrive at the track even with a 4l80e) and with a 3.54 its pushing the rpm's a little more than I want to go even with a 30in tire. In the mean time until the car makes that level of power the 3.54's would be ok, I just don't want to have to completely redo the rear again.

What rpm are you shooting for? Any block / rotating assy/ valve train that will handle 1000hp will easily go 8000 RPM. With a 30" tire and a 3.54 rpm will be around 6600 with 5% slip at 160 mph.
Doug

 

[YellowDodge67]

What rpm are you shooting for? Any block / rotating assy/ valve train that will handle 1000hp will easily go 8000 RPM. With a 30" tire and a 3.54 rpm will be around 6600 with 5% slip at 160 mph.
Doug

Was trying to keep under 6500rpms

 

[dvw]

Was trying to keep under 6500rpms

Why? Stock crank, stock rod, TRW piston motor will go 6500. At 1000hp those part longevity could be very short. Not to mention 1000 hp is borrowed time on even a low deck stock block. A low deck with good pistons and rods would probably survive 800hp, for a while. 1000hp+ I'd invest in an engine diaper, a bag of floor dry, and a broom.
Doug

 

[YellowDodge67]

Why? Stock crank, stock rod, TRW piston motor will go 6500. At 1000hp those part longevity could be very short. Not to mention 1000 hp is borrowed time on even a low deck stock block. A low deck with good pistons and rods would probably survive 800hp, for a while. 1000hp+ I'd invest in an engine diaper, a bag of floor dry, and a broom.
Doug

The next motor going in this car is gonna be a factory block with a low fill and a girdle. Was trying to keep the rpm's reasonable to keep the block together for as long as possible before going to an aftermarket block because not only are they pricey but they seem to be hard to find new unless I go aluminum which is $$$. Being primarily a street car it isn't going to be turned up 90% of the time, it may see full throttle fairly often but at a lower and more survivable boost/power level, so I'm hoping to get a few years out of the above combo.

With that said, kitty litter and a mop will be on standby lol

 

[dvw]

The next motor going in this car is gonna be a factory block with a low fill and a girdle. Was trying to keep the rpm's reasonable to keep the block together for as long as possible before going to an aftermarket block because not only are they pricey but they seem to be hard to find new unless I go aluminum which is $$$. Being primarily a street car it isn't going to be turned up 90% of the time, it may see full throttle fairly often but at a lower and more survivable boost/power level, so I'm hoping to get a few years out of the above combo.

With that said, kitty litter and a mop will be on standby lol

Never say never. We have quite a few laps on the 360 with the cast crank. That being said it has a diaper.
Doug

 

[fk5dave]

i just blew up a 8.75 on my 68RR with only 15in radials. lol. it was a year old rebuild, 742 case, 3.91 gears, sure-grip posi, healthy 500ci stroker motor, clutch dump on a back road. kaboom! Didnt show up right away. next time i drove it, it sounded like a skipping ratchet in the back end. took it apart to find to find a bomb went off. ended up ordering a moser dana 60 with a detroit locker and 4.10s!

 

[1967coronet440]

Someone make this a sticky for all the guys that want to build stroker motors and still run an 8 3/4

 

[Cranky]

Anyone ever compared an 8 3/4 clutch unit to a 60? BIG difference. I used to post the difference from photo bucket but can't anymore because they are holding my pics hostage unless I up with some money. Screw that....

 

[Cranky]

Someone make this a sticky for all the guys that want to build stroker motors and still run an 8 3/4

Done!

 

[YellowDodge67]

Took the rear apart the other night, looks like the shaft that held the spider gears shifted and got taken out by the pinion gear. Going to put a used stocker in there for the time being so the car can move around for the winter. Is there anything special about replacing the bearings on the axles or is it just press off and press back on?

 

[5.7 hemi]

I’m building a Dana 60 cause I’m sure that my 8 3/4 in my Dart isn’t gonna hold the 470/4 speed for long. Plus I can sell it to help offset the cost of the Dana.

 

[lyndondb]

I got a dana 456 with Moser axles. bullitproof

 

[tomlin]

YellowDodge67. I have seen that kind of damage before. Usually on a open differential and usually caused by somebody doing a single wheel John Force burnout for a 1/4 mile. LOL. Ask me how I know? The spider gears spin so fast they gaul the cross shaft. The shaft moves out of place and hits the pinion. Major carnage. This could have happened on any open rear axle, Dana or otherwise.

 

[Mike67]

Am I misunderstanding...you need a rear that will support 800-1000hp but are going with a mildly built trans????
The rear will run $2500 +/- but a built 727 is probably going to be north of $4000...I'm not a racer just curious of your expectations....

 

[Cranky]

I did that (only not so bad) to a 9 1/4 by doing the one wheel peel too much with my SWB pickup that had a mildly healthy 360 in it. I tried preloading the chassis to get it where it would plant the right rear better in an effort to make both wheels track but I think pickups have too much flex for it to work well. Anyways, I stuck in an 8 3/4 with a SG and never looked back.

 

[YellowDodge67]

YellowDodge67. I have seen that kind of damage before. Usually on a open differential and usually caused by somebody doing a single wheel John Force burnout for a 1/4 mile. LOL. Ask me how I know? The spider gears spin so fast they gaul the cross shaft. The shaft moves out of place and hits the pinion. Major carnage. This could have happened on any open rear axle, Dana or otherwise.

Pretty much exactly how it went down lol

 

[Photon440]

i just blew up a 8.75 on my 68RR with only 15in radials. lol. it was a year old rebuild, 742 case, 3.91 gears, sure-grip posi, healthy 500ci stroker motor, clutch dump on a back road. kaboom! Didnt show up right away. next time i drove it, it sounded like a skipping ratchet in the back end. took it apart to find to find a bomb went off. ended up ordering a moser dana 60 with a detroit locker and 4.10s!

View attachment 536140

Perhaps the 3.91 gears were thinner and weaker than numerically lower ratios, or the pinion gear was just too small? At any rate, Chrysler knew of the weakness. This 1968 Field Bulletin says that the 8 3/4 3.91 was barely strong enough for even the 383 4-speed combo.

 

[YellowDodge67]

Am I misunderstanding...you need a rear that will support 800-1000hp but are going with a mildly built trans????
The rear will run $2500 +/- but a built 727 is probably going to be north of $4000...I'm not a racer just curious of your expectations....

Already had the trans, rear was stock

 

[1967coronet440]

700-1000 Rwhp you can count on spending 10k+ in the trans, rearend and driveshaft alone.