How strong is a 8.5 dif.... REALLY

I have a 8.5 dif in my Cutlass. I've done a few things to improve it

-Moser ends with c-clip eliminator
-welded tubes to carrier
-true trac posi
-Dutchman 30 spline axles
-ARP gear and carrier bolts
-T/A stud girdle
-Richmond 456 gears.

How much power can I send at this thing before I grenade it?

My car has a Viper T56
I just finished dyno proving that my 632 BBC has 800 hp and 765 ft/lbs torque.

http://www.youtube.com/watch?v=6G0DWTiwQ0M

I am currently upgrading suspension components but wondering if this rear end will do.
Any guys out there REALLY punished one of these diffs?

Thanks!! :twisted:

mean78malibu said:

The posi unit will most likely go before anything else. I'm putting down about 200 less and will use the trans brake next season with the same setup except I have moser 30 spline axles on drag radials. The T56 will be harder on it depending on how you drive : )

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Yes I was thinking the same thing. I've seen pics of scattered worm gears from truetracs on a mustang site.

Thinking about a spool and 33 spline axles, but this car will be mostly street driven.

The traction issue was bad with my last engine (496) but slicks and a few other improvements should help.

Come on! Someone out there must have beaten one of these things to death!

Let's hear some stories.....

I'm on the brink of going with a Dana 60........ I really (REALLY) didn't want to spend $$ on another diff :roll:

DFWMalibu said:

I see the transmission grenading before the rearend does.... never seen a t56 hold any torque... don't know if yours is stock or not...

Chris K.

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My t 56 is out of a 2003 viper and has had all the upgrades(steel shift fork, solid keys,etc, etc)

I basically wanted to hear from anyone running an 8.5 to the point where they broke it and what it took to do it.I'm sure mine would have survived on the street, but at the track I'm not so sure.

I've already made up my mind to go with a Dana 60. In fact I've already acquired one and am in the process of cutting and prefabbing the ears and brackets. Don't have the $$ for one from Strange. There's a guy locally running one in his Monte. It's a really nice piece of equipment, but cost the better side of 3k all in and I don't have that kind of cash right now.

Plus there's also the cool factor of looking under the car and seeing that massive dif.... 8)
Still want to hear some stories though.......