Rear Axle Advice

[ericwevans]

So it is getting time to put the axle together for my truck.  The plan is to be making around 600 HP, 5 speed manual trans, the truck currently weighs 4200 lbs without driver.  On 30" tall slicks with 5.14:1 gears I estimate going through the traps at 120 in 4th at my shift point.  What I do know is that the truck will be street/strip with a Detroit Locker.  So now for the advice...

Is a Strange iron S Series case and 35 spline axles overkill, can I get away with the stock case and Strange 31 spline axles?  If you need more info for a recommendation let me know.  :-)

[ScotiaFE]

I use 31's in my junk. They haven't broke off yet.
You're clutch will be the biggest factor in this equation. 

[Tommy-T]

Curious about the S series case as well. Seems difficult to find someone who has actually used one.

I need a 3.250" case for the H Detroit locker I bought off of ebay. Man, the big Detroit's are cheap cuz you need an aftermarket case.

The S series can be bought for $225 most anywhere. Like above, does anybody have any actual run time on these?

[ScotiaFE]

Curious about the S series case as well. Seems difficult to find someone who has actually used one.

I need a 3.250" case for the H Detroit locker I bought off of ebay. Man, the big Detroit's are cheap cuz you need an aftermarket case.

The S series can be bought for $225 most anywhere. Like above, does anybody have any actual run time on these?

Oh you mean the cheap ass one. Works great in my cheap ass junk.
I think I got it for about $180 on sale with a coupon about 4 years ago.
It needed some grinding on the bearing support to fit the gear in.
They look way stronger than a factory N case, thicker and such.

[ericwevans]

Thanks for the input, I am concerned about the gear banging as well with the 5 speed.  Scotia', if you don't mind answering, how heavy is your ride and what gear are you running?

[ScotiaFE]

The Fairlane is a portly 4000LBS +or- with me in it.
It is a full dress thing with every option, except weight reduction.
We use a McLeod Adjustable clutch, a Jerico 4 Sp and a Cal Trac slung 9 inch with all the cheap
after market stuff Summit flogs. Normally we use a 4.57 and try not to spin the tires too much.
What you should be thinking about is Starting Line Ratio.
Depending on your first gear, and the type of launch you want.
Do not think like auto guys. They have a converter to do the thinking for them.
You have a clutch. You must do all the thinking.