8 3/4 vrs 8 1/4 strength

[Wicked72]

So i have been looking for and 8 3/4 after i foolishly sold mine with an 89 case... had the money for new dana and a four link and then my job went south.... figures... so now i have a 8 3/4 from an e body 41 case and an 8 1/4 from a 73. Ive been told the 8 1/4 is just as strong and also have been told its very weak so i am not sure what to think. I know the 41 case isnt strong like the 89 or the 42 but how weak? So id like to know how strong the 1/4 rear is compared to my 3/4 with the 41 case. Obviouesly the 3/4 is easier to work on but i just want to know abt strength.

[chargd72]

1/4 is strong enough to handle any stock small block. But if you have a performance engine with some tires that hook, you'll need a 8.75 under that heavy b body. My built 318 charger just got it's 8.25 rear swapped out for a 8.75 with a 489 case. Complete overkill for now but I'll need it when my 408 stroker goes in. Probably doesn't answer your ? directly but most people swap them out for a reason.

[chargd72]

Another reason not to push it with a 8.25 is that the axles are kept in with a retainer pin in the center section. So if those axles snap they'll do a crap ton of damage as they fly out. 8.75 axles are held in from locks on the drums. So if something broke on that, it would be contained inside. But you need a nasty engine to do that to a 8.75.

[Wicked72]

thats says alot actually. so screw the 8 1/4. im putting in a 400 just has a edelbrock intake and a set of headers so its not much power anyway. however i will be making a stroker out of it. so whats a ballpark on how much can a 41 case handle?

[cdr]

the 741 is not as weak as its rumored to be, different gear ratio's are harder to get,the 742 has a larger inner pinion bearing ,i think if you broke a 741,you would have broke a 742 & 489 also   

[FLG]

Without slicks it would be tough to break either one..imo run whichever one has a sure grip.

[Wicked72]

no sure grip in the 8.75 or the .25 but i may look into either finding a center section with it all or just build the 41. its got 323 gear so its not to bad but i think i may want to got with 391. need to get on a a calculator to see what my rpm range will be thinking 295/50/15 in the back havent decided yet.

[Wicked72]

btw no slicks on this car just wide street tires

[John_Kunkel]

I ran a Max Wedge car with a 741 into the mid-twelves with 10" slicks. The 741 gets little respect but it's tougher than most give it credit for.

[Wicked72]

need to get a sure grip!! I think 3:23 gears will be just fine rpms will be nice at highway and still have a little punch.

[randy73]

In my 74 duster I put a modified 440 in and the 8 1/4 held up fine. It is just hard to find gears for, it is  good rearend,people tend to trash products, because everybody thinks bigger is better.

[Cooter]

I've run 6.80's(8th Mile) on a Nitrous'd 505 Inch BB, on DOT's with a "741" 3.91 Sure Grip.

Just like the 18 Spline "Hemi" 4-speed VS 23 Spline. If you know what your doing, you won't break either one, but if you like 7500 RPM Clutch dumps on slicks, with dead hook, you will put even a Dana 60 in a bucket.