need rear end advice

[Blackhawkdc]

Ok, here's the deal, I've got a stock GM 12-bolt rear end with 3.73 gears bolted to an open differential. I'm adding a 496 stroker to the truck for go-go power. I need advice on what to run for gears, and also for a differential, whether it be a limited slip unit, locker, or spool. I'll be pushin close to if not over 600 horse/torque. The tranny is a TH400. Tires will be around 29-31 inches, 2wd. What are people's recommendations? It'll be mainly a street truck also. I also need to keep the cost down if it can be helped. So please, give me all yere advice. Thanks again.

Oh, the truck is a '69 shortbox, stepside with rear coil springs

[bigjimzlll]

do not weld them..its not NHRA legal or safe..a spool on the street is not a good idea...a posi and 600+ HP...nope.. the locker is the best way to go

[Fuzzy]

spool is cheap and chirping the tires as you go around corners is cool, but get a c-clip eliminator so when you start breaking axles you don't loose wheel and tire and axle.

[mikep]

$200-$300 for a junkyard dana 60 with 4.10 gears and powrlok positraction ( thats the high estimate . Ive bought them for from $35 to $75 ! )

$65 for a powrlok rebuild kit ( chrysler )

$320 for a set of good aftermarket axles in whatever bolt pattern you want with bearings and retainers that dont need those worthless C clips

$180 to narrow the Dana 60 with new big Ford tube ends. You reuse the brakes from the piece of crap 12 bolt truck rear end.

Total of $765-$865 for a bulletproof dana 60. A good rebuilt powrlok Dana 60 will be a joy to drive on the street plus you won't have to have it set up as the gears will be what you want for good performance.

[kwmech]

With that much HP you will be rebuilding that 12bolt just about every time you run on the track, probably should go to a dana 60 with a limited slip, my gear choice with a 30'' tire would be a 3.54 ratio. This would give a fairly decent rpm on the street. I custom build axles all day long for hot rods and 4wds. Personally in my longhorn I just put together a 14 bolt with a detroit locker and 3.42s and I am running a fuel- injected, punched out 454. I am guessing my hp to be around 350 to 400

[Blackhawkdc]

I'd love to go with a built Dana 60, but I don't have the money. Not this year at least. Any other ideas? Considering this is a truck, I would be lead to believe that the rear tires will break loose before the 12-bolt breaks.

[mikep]

Welding spiders is illegal on the track and stupid on the street .

Anyone even make a spool for 12 bolt truck axles ? If so ...why ? You'd still have to use a C clip eliminator. Dont even think about using a minispool on the street with 600 HP. Even on street tires you'll break that cross pin before you can say " damn... I spent $5000 on an engine but I was too cheap to spend $750 on a rear end that would handle the power "

A new detroit locker will cost you $500 and add $250 or more if you have someone install it . You could have built a good dana for that. And you'd still have to spend money on the c clip eliminators and a good set of axles .

If your'e that cheap you could always go with a govlock . hahahaha . snappity snap snap ...


The whole point here being if your'e not hooking the tires then whats the point? 600 HP is the same as 300 HP if the tires are just spinning except the other 300 HP cost a whole bunch more money! Get the tires to hook up and get a rear end that can handle the power. I'm a firm believer in building the drivetrain to handle the power before you ever start building the power!

[crazy4chevs]

9" from a 70's lincoln- they even have factory discs and are only 1" wider than the 12bolt, you can get detroit lockers for them too.

[mikep]

Forget about the mid 70's 9 inchers for anything over a few hundred HP . Theyre 28 spline carriers with small bearing ends and have poor gearing. You'd need a new set of housing ends welded on along with new axles and a new 31 spline center section along with corresponding trac loc or detroit locker. You'd have a thousand bucks+ into it before you knew it.