I'm going to begin my build for a 383 twin turbo and figuring on around 800 hp but i'm not to experienced in rears i dont know weather to build the stock or ford 9 inch or buy a complete moser setup im lost
btw its a 1990 iroc-z
Blue
Thanks

 

if you are going to beat on the car, the best bet would be a bolt in 9" or dana60

 

Don't waste any money on the stocker--go with the Moser unit. If that's a real horsepower number I'd suggest spending the extra $$$$ and going with the 40 spline axles and spool for innards. Minimum IMO would be a 33 spline axle if you plan on being on the street with a posi unit instead of a spool.

 

Assuming at least a 3 speed tranny, 33-35 spline axles should be about right. 40 is a little too much.

Any of the aftermarket bolt in third gen diffs will do fine. 9", Dana 60 or 12 bolt. For a complete diff, ready to bolt in, they're all in the $2500 range depending on exactly which options you get.

Don't expect a high HP engine to let any part of the factory driveline survive. Everything will have to be upgraded.

 

There is no way the stock rear end can be built to handle that amount of power. You are going to need a well built 9 inch for that. Even a stock 9 inch would break with that amount of power. The aftere market nodular cases are much stronger than stock, and 35 spline axles shoudl be used. There are 2 choices for differentials with the 35 spline axles. There is the Detroit Locker and the Wavetrac. The locker would hold up fine, but the Wavetrac is sesigned for 1200 HP and it's smoother, but $400 more than the locker. About $2500 plus shipping will get you a well built Moser 9 inch.

 

been running my stock 4th gen 10 bolt behind my twin turbo 401...no problems. Cracked one worm gear in my previous 10 bolt and replaced it with another 4th gen 10 bolt. Been 9.72 at 142 with no problems.

If you are an automatic with no transbrake in your future, a 12 bolt will be more than enough. 9" and Dana 60 stuff is overkill IMO. If manual trans and clutch drops under boost with good twin disc type clutch then yes 9" all the way. 12 bolt is lighter and will have less power lost through it.

When I upgrade my rear it will be a bolt in 12 bolt. A strong built 12 bolt should survive transbrake launches too, as long as the car isnt too heavy.

 

oOrr89RocZ, you're right. I've been dealing with a bunch of 9 inch stuff the last few days and I have 9 inch on the brain. A good 12 bolt would probably hold up fine. Moser offers a 35 spline Wavetrac for the 12 bolt too. There are several good 33 spline 12 bolt differentials like the Eaton Posi, Detroit Locker and Truetrac that would work fine.

 

do a search on moser customer satisfaction... (not good http://www.ls1tech.com/forums/gears-...ice-moser.html ) i went with the strange s60. they start around 1900.00 maybe cheaper for just the basic basic rear i would not waist my time with a 12bolt unless i was auto and had a mild 400-500 flywheel build that i never planned to mod again


these are the two tough choices...
(strange) s60= id use Central Racing Parts (Carl)
pro/ very nice bolt in looks very factory( like a 9bolt on roids) and can use all factory part for mounting it (even stock tq arm)
con/HAVE to get a shorter driveshaft adds a bit to price (but any rear upgrade why would you think stock shaft was good? and some aftermarket arms need to be shortened (factory arm is said to slide forward enough in the clam shell) and cut the arms second set of mounting holes off)

9" go prefab I would use Midwest Chassis & Performance, Inc.
pro/ comes with TQ arm, has removable centers for the person who wants fast ratio changes, lighter of the two and looks neat (cool factor)
Con/ costs more, centers aren't cheap! requires there rod end TQ arm so it will make noise no way around that and since your a thirdgen you may need to have it made just for your length and mount

 

I'm leaning towards S60 myself.