Safe Limits For 8.75 Rear

[BS CUDA]

Here is a little more to think about - I have well over 200 passes on my 8 3/4 - 4.10, with 295/55R15 Mickey ET streets and I hook hard when heated properly. The pumpkin , gearset or bearings have never even come close to letting me down and I don't even give them a second thought after launching hard all weekend then going for a cruise down the highway. Engine is a "mild" 500CI stroker with 620torque. I have however wore out the Auburn center section of which they replaced for $100.00 as they have a 4 year warranty. Do keep in mind that I run a shop that sells and installs this stuff so breaking it is hardly a concern in the $$$$ aspect (cheap labor) Run the 8 3/4 till it pi$$es you off - building the 1st one is still cheaper than retrofitting a 60 - and besides like CP says if your up in smoke all the time it will last forever!!!   

[Road_Runner]

Here is a little more to think about - I have well over 200 passes on my 8 3/4 - 4.10, with 295/55R15 Mickey ET streets and I hook hard when heated properly. The pumpkin , gearset or bearings have never even come close to letting me down and I don't even give them a second thought after launching hard all weekend then going for a cruise down the highway. Engine is a "mild" 500CI stroker with 620torque. I have however wore out the Auburn center section of which they replaced for $100.00 as they have a 4 year warranty. Do keep in mind that I run a shop that sells and installs this stuff so breaking it is hardly a concern in the $$$$ aspect (cheap labor) Run the 8 3/4 till it pi$$es you off - building the 1st one is still cheaper than retrofitting a 60 - and besides like CP says if your up in smoke all the time it will last forever!!!

I really appreciate your input.  Have you done anything special setting up your 8.75?  I have a very used auburn rear chunk & 3.91 gears in an E body rear I could use, but to do it once I was thinking about taking the original open 3.23 center section in the car at the moment and just replacing the guts with a new Truetrac sure grip, new ring & pinion, bearings, seals, etc.  I was looking for input on whether I should change out the axles which are original with 102K on them.  If so, whose axles would you recommend?  How about drive shafts, did you use your original or go with an aftermarket?  If aftermarket whose?  Sorry for all the questions, but like I said I was hoping to keep the original rear in the car if I could because I figure once its replaced its not likely that I or anyone else will put it back.

Thanks, Jim

[PlumCraZRT]

If you leave it behind an automatic, it will be far more robust.  Dynamic loading is what will break it, and an automatic just can't produce the same dynamic loads that popping the clutch can.

[Road_Runner]

If you leave it behind an automatic, it will be far more robust.  Dynamic loading is what will break it, and an automatic just can't produce the same dynamic loads that popping the clutch can.

You're right and this whole thing has me at least considering doing just that and just keep it all original driveline-wise.  Otherwise, I'll probably go the safer route with the manual trans and just put in the Dana.  Seems like my planned build is in the grey area where an 8 3/4 may be fine but one really good launch one day could turn it into shards.  If it was just a matter of breaking parts I wouldn't be as concerned but I've been at the track when a car either broke an axle or center section and did a snap turn right into the wall.  That would suck.

Later, Jim