Anything wrong with the 8-3/4 "741" case?

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MileHighDart

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I have an extra 8-3/4" center chunk under by bench. It's a 741 case open with 2.76 gears.

I was thinking of digging it out and swapping in some 3.55 gears and ad a suregrip unit.

But shopping around a bit there seems to be very little stuff available for the 741 case. But lots available for the 742 and 489.

Is there anything wrong with upgrading a 741, that people dont like to use it ?
Not for racing, just general cruising, behind a basically stock 5.9
 
The 741 has a 1-3/4" straight pinion and is the weakest of the three. Everyone upgrades to the 742 (preferred by drag racers) because of the 1-3/4" tapered pinion or the 489 which had a 1-7/8" tapered pinion. Nothing wrong with the 741 on the street, but as you found out very little aftermarket support or factory parts left. Randy's ring and pinion and Dr. Diff have parts.
 
Nothing wrong with them for your intended use. I drag raced a 741 case into the 11s with my dart and never broke it. Stock small bolt pattern axles too... lol
 
You have already mentioned the biggest problem with the 741. That being parts availability. It is supposedly the weakest of the three styles so it wasn't as well supported. I know of several 741s being beaten on severely including one of my own that never broke. If you have one, by all means put it into service.
 
The Max Wedge cars came from the factory with the 741 case.
On the street there should be no issues using one.
 
741 Has always been solid on my B body. No issues 13 years.
 
nothing wrong with a 741 case..

a lot of guys thing they are junk because of a magazine article many years ago they bad mouthed them. was one of the mopar magazines.. forget which. kinda like the stupid *** article that said the 73-up b body spindle shouldn't be used on abodies.. :)
 
Yep had one in my '70 Challenger with a 440 and a 4 speed. Never a problem.
Just bought one off a member here.
 
741 case w/3.91 sure-grip in my 65 cuda. Works great! 65'
 
There is absolutely nothing wrong with the 741 chuck other than the lack of gear sets. Factory did make sets down to 5.13, long , long shot to find a good used set, 3.55, 3.23, and 2.76 much more common. Current aftermarket support ratios are 3.55, and 3.73.
Any claimed weakness is horsesh!t, 1 3/8 diameter pinion is only .060 smaller in diameter than the fabled 12 bolt generious motors rear....lots of 741 housings ended up in pick up trucks, just use your imagination on how hard farmers "used" their trucks, they were also found under 340 "A" bodies, don't be afraid of a 741 housing.....I'm not, I wack mine to wheels up launches to the tune of 11.14 sec. 1/4 mile times
 
You would be hard pressed to tell the difference in strength between any of the 8 3/4 cases. It's splittin hairs at best. The 741 is plenty stout.
 
It's been a few years but a local driveline shop did a 741 with 4.30 gears for me. Even though it is said that nothing more than 3.73 are available for the 741 it's possible that there might be more out there.
 
HemiSSDart said:
The 741 has a 1-3/4" straight pinion and is the weakest of the three. Everyone upgrades to the 742 (preferred by drag racers) because of the 1-3/4" tapered pinion or the 489 which had a 1-7/8" tapered pinion. Nothing wrong with the 741 on the street, but as you found out very little aftermarket support or factory parts left. Randy's ring and pinion and Dr. Diff have parts.
Click to expand...
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741 is a 1 3/8, 742 is 1 3/4 and the 489 is a tapered 1 7/8.
741 were put behind 340s and 383s from the factory.
 
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