741 open case v 7 1/4 LSD

-
Ozabody

Ozabody

Member
Joined
May 21, 2022
Messages
7
Reaction score
14
Location
Australia
Hi everyone, any ideas which differential to use.

Engine is 440rb in A body with XE274 hyd cam 727 auto shift kit with 2800 stall, 17x8 wheels.

1st differential is 7 1/4 LSD 3.89 ratio.

2nd differential is 8 3/4 3.23 ratio 1968 C body 741 case open wheeler.

Apparently both differentials have the same pinion size.

I’m guessing spider gears are stronger in the 8 3/4

I’m on a tight budget so which differential would survive better?
 
8-3/4… For So Many Reasons! Look at the 2 inch axle tube size into the center section for starters, and then go from there. Just the spindly size of the housing with tubes by itself would scare me far away from the 7-1/4, much less my personal experience in breaking them. And with nowhere near the torque output of a good 440, at that!
 
Last edited:
The 7.25 sure grip axles were pretty strong for the intended purpose. With that said, anything over 300 pounds of tq with traction will eventually cause issues.
 
ANY of the 8 3/4 units are night and day stronger than the 7.25. All three 8 3/4 castings are so close in strength it's splittin hairs to decide which is strongest. But they are ALL much, MUCH stronger than ANY 7.25. LSD or not.
 
Agree with RRR. Most like the 742 or more so the 489 case over the 741. 741 being the weakest.
 
Don't even consider the 71/4 all that will so is cause damage to your trans when it ***** the bed .
 
Thank you everyone for your valuable experience, greatly appreciated. I certainly will not be using the 7 1/4
 
You must log in or register to reply here.
-

Back
Top