Rear End Repercussions

Alright, time to start thinking about my rear end. i'm sure i want it to be a good old Ford 9 inch. i know there are gurus out there who know the end-to-end length needed for a fox-body, and i need to know it. i also need axle length, ideal # of splines, and a good axle retention method for my application, which is thus. i want this car to be able to launch straight, but not totally lose it in corners. now origionally i wanted to put in a steeda 5-link: if i were to use the steeda weight jacker aluminum lower control arms with this, would i still be able to get off the line? or would something better work? or should i perhaps just stick with 4-link w/adjustable uppers? important note: i'm converting to coilovers. finally, i will require a differential that has a strong locking characteristic, yet provides some limited-slip. a spool is out of the question. i thought about the airlocker, but i can't afford the extra weight unless i can use it to enhance traction. any advice you guys can give me is great, or just point me in the right direction. thanks!


P.S. i'm strictly an amature when it comes to differential terminology, so help me out here =)

9inch is not needed unless you making ridiculious hp. Second is that why you were not gonna use the Steeda 5-link?

A 9" is helaciously overkill. An 8.8" with some 31 spline mosers will take pretty much anything you will make in a street car.

Yep, what they said.

You will not need a 9". And why would you need a 5 Link?

What are you trying to accomplish with your car?

hmm, one of my questions answered (# of splines)

one thing cleared up (8.8 vs 9). the reason i wanted a 9 was that you just can't break those... but, i can always reinforce an 8.8.

as for the 5-link, i wanted it because of the weight and axle control advantages over 4-link+torque arm. it seems that it would interfere with my launches by providing unneccesary squat control, so i will just put straight lower and adjustable uppers on it. with coilovers and appropriate adjustable shocks, i can make it hook as hard as i want. also, regular 4-link will allow me to run relatively inconspicuous rear-exit exhuast. if i ever build another stang set up for autox or circuit, i'll use the 5-link.

and, to make my other question clear, which differential should i go with? this will be a streetable drag car, to answer skyline's question. in race trim (small blower pulley, race gas, slicks), i'm hoping to make somewhere in the neighborhood of 700-800 horse/tq.

oh, and for those of you who dont' know much about the 5-link deal, http://steeda.com/

and one more question: steeda is primarily a road-race suspension company. what is the better choice for a steet/drag car?

Ok well with those HP/TQ numbers I can finally answer some of your questions. First I would just build up and 8.8 but if you go 9" my advice stays the same. 31-spline should be ok but with those numbers and slicks I would go with 33 just to be on the safe side. It cost you no more cause your getting a new diff any way.

At those hp/tq levels anything but a spool your going to break eventually over time(not a long time). This includes ECTED, Air Locker, Detriot Locker. If you think this is not true call up rears and gears and see what they say. But it will take some time but not a lot to break-em. My suggestion ECTED or Air Locker(both rebuildable and strongest of the bunch) cause you want a streetable car and I have driven a detriot Locker equiped car and that is far from streetable.