What is the best, strongest 8 3/4 housing?

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HemiMark

HemiMark

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In order, what is the best 8 3/4 housing

742
741
489

?
I have a 742 with 4.30's and a 741 with 3.91's
 
All based on pinion diameter...
the 741 is the weaker
the 742 is strong with a larger non tapered pinion.
the 489 has the largest pinion but it tappers down some.

I like the 489, but some argue the 742 as they're fav.
489 is the most hd of them all by the book.
 
I'm not building a race car or anything. It's going behind a stock 340, 727 auto so does it bother anyone tha the housing is a 741? Just asking because I could put the 3.91 gear set into the 742 case...
 
How strong do you guys think the 741 is? Handle mild 440 easy enough?
 
HemiMark said:
I'm not building a race car or anything. It's going behind a stock 340, 727 auto so does it bother anyone tha the housing is a 741? Just asking because I could put the 3.91 gear set into the 742 case...
Click to expand...

I have been abusing 741's behind a 360/340 4spd for years with no issues what so ever.
:burnout:
I have always been good with the idea that a 741 can handle up to a built 383 and live for a good amount of time, give or take.
Some people might find their style of driving will allow a 741 to live for yrs behind a 440.
 
HemiMark said:
I'm not building a race car or anything. It's going behind a stock 340, 727 auto so does it bother anyone tha the housing is a 741? Just asking because I could put the 3.91 gear set into the 742 case...
Click to expand...

Gear sets are case specific. 741 might live forever if you don't have a manual trans or big sticky tires.
 
It's not the case that is strong or weak. It's the pinion that must be used. You cannot swap the ring and pinion for a 741 case into a 489 or 742 case.

The 741 will probably be fine behind an automatic.
 
I guess I should have said I can put a "new" 3.91 into the 742 case...., not swap them...... sorry
 
HemiMark said:
I'm not building a race car or anything. It's going behind a stock 340, 727 auto so does it bother anyone tha the housing is a 741? Just asking because I could put the 3.91 gear set into the 742 case...
Click to expand...

Sorry, I only got this far in the thread and had to comment that my 741 housing with a suregrip and 4.10's has seen serious street abuse for a good 10 years running stright with 6500/6800 RPM "Side stepping the cluth" shifts.

It has lived behind a reasonably stout "Street" 360. The top equipment is has been used with is RPM heads and various intakes and various cams up to 250 @ .050 duration, super copmp headers. It's an 11-1 engine.

OH, as D-Devil made mention of, no real sticky tires have been used. Various street tires on and off the track at various pressures.
No issues.
 
rumblefish360 said:
Sorry, I only got this far in the thread and had to comment that my 741 housing with a suregrip and 4.10's has seen serious street abuse for a good 10 years running stright with 6500/6800 RPM "Side stepping the cluth" shifts.

It has lived behind a reasonably stout "Street" 360. The top equipment is has been used with is RPM heads and various intakes and various cams up to 250 @ .050 duration, super copmp headers. It's an 11-1 engine.

OH, as D-Devil made mention of, no real sticky tires have been used. Various street tires on and off the track at various pressures.
No issues.
Click to expand...

i appreciate all the input. Now that I have confidence in the 741 I will sell the 742 to my buddy.
 
I think there was a big writeup comparing all sorts of different pinions across brands somewhere, I want to say it was a tech archive somewhere. I think it was Dr. Diff that did the writeup. One thing I think I remember being in there is that the 741 still has the same size if not bigger pinion than a Ford 9 inch, so among Mopar cases I think it tends to be how much overkill do you want. The 9 inch does have the extra pinion support bearing though, so maybe it can get away with a smaller gear. The other problem is that both the 741 and 742 have a step in diameter in them at the pinion nut. That's going to be the weak point of the metal, so the 489 is probably the strongest in design, even with the taper.
 
HemiMark said:
In order, what is the best 8 3/4 housing

742
741
489

?
I have a 742 with 4.30's and a 741 with 3.91's
Click to expand...

Hmm...those are all CENTER SECTIONS,the housing is what the carrier goes into of those the 742 and 489 are the strongest:iconbigg::iconbigg:
 
Mark,
I woulld not be afraid of a 741. It seems that's all I have and haven't broke one yet. Back in the day I would back my up my car quickly (69 Dart GTS) while it was still rolling backwards , then put it in 1st gear and side step the clutch. Man you talk abour laying down some black.
 
Go 489 just know they have a crush sleeve in them (it's weak point), however you can now order a solid one and make the 489 bullet proof! Both of my 489s have the solid sleeve in them.
 
This topic is one of the most overplayed tiresome crap that goes on in the mopar world. Someone wrote a piece saying the 741 was weak and it gets lots of run. It's ring gear deflection that is the weak point, that's a case issue at the caps, not the pinion or pinion bearings. They all have the same caps.

All of those cases are fine behind what you have.

Actually, the only thing that doesn't cross between cases is the pinion/bearings. Ring gears are the same.
 
crackedback said:
This topic is one of the most overplayed tiresome crap that goes on in the mopar world. Someone wrote a piece saying the 741 was weak and it gets lots of run. It's ring gear deflection that is the weak point, that's a case issue at the caps, not the pinion or pinion bearings. They all have the same caps.

All of those cases are fine behind what you have.

Actually, the only thing that doesn't cross between cases is the pinion/bearings. Ring gears are the same.
Click to expand...

Like I said.... I'm good to go with the 741 with the 3.91, 727 auto and a pretty much stock 340. :study:
 
Yes Mark, It's OK. That case works fine for what you are planning.

I'll happily take all those junk, weak sauce 741's with the equally junk cone sure grips since they are worthless... LOL

Each of the cases have a weak point in original pinion design.

Unless you are dead hooking a big HP car that weighs a bunch, any 8.75 rear is good. And when you get to that point, there isn't a 8.75 that will live in that environment for long.
 
crackedback said:
Yes Mark, It's OK. That case works fine for what you are planning.

I'll happily take all those junk, weak sauce 741's with the equally junk cone sure grips since they are worthless... LOL

Each of the cases have a weak point in original pinion design.

Unless you are dead hooking a big HP car that weighs a bunch, any 8.75 rear is good. And when you get to that point, there isn't a 8.75 that will live in that environment for long.
Click to expand...

Well, you hear so many stories about which is better..... I'm glad I asked. I have a Dana in my Duster!
 
741 will be fine for what you are using it for.
The only downside is parts are a little harder to find for it but they are out there.
 
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