size to narrow a ford 9 to?
 

got myself a ford 9" yesterday. its big mabey 65" hub to hub


what width do I need to narrow it to for my 73 rx3? I dont want to tub it and ill be using 8.5 inch street slicks.

also because the third member is off center on a ford 9 does that mean one side gets narrowed mor than the other?

thanks
Tyler

Yes, one side will be narrower than the other. You narrow it to whatever fits after you pick your wheels and tires (plus brakes).

Here is a pic of mine in the car, before I took it out.

http://i22.photobucket.com/albums/b3...9inchincar.jpg

Looked like this.

http://i22.photobucket.com/albums/b3...3newslicks.jpg

Just take your old rear end to the shop with the 9" and have them match it up. That is what I did.

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ok ,
what did you guys use for posi in the diff?
Spool? or proper posi?

also gearing i think i might use somthing in the 4.3 range what are you guys using?

thanks
tyler

Gearing depends on the tire height and the rpm range of the engine. The choice of posi/open/or LSD depends on what you want fromt he vehicle. Do you drive it everyday? Gives us some more info, and we can better help you.
Example, I had a car that I drove for fun, and focused on drag racing, so I had an aluminum spool, I shifted at 9200 with 26 inch tires, and a target of 120 mph in the traps, so I put 5.14's in it.

My car will mainly be used for street, so no spool, LSD, and 4.11 gears. The thing about the 4.11's is it seems to be the highest gear you can find (easily) in a production car. I.E. you can get a set from the junkyard. If you go higher, you will be buying aftermarket.

I should also clarify, that I am running an 8.8", not a 9". I did this to shave some weight off of the swap, and get a little better power to the wheels. :)

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well the motor is a just built S5 high comp full extended briged dowelled motor with big ass turbo. porbably putting out over 450 whp,
I want it to be able to turn corners as well as go straight I think im going with a 4 link setup and 1 panhard rod in the back with coils and disk brakes.


and The car needs to be faster than my buddys turbo+nitrus 240z wich will be putting out around 500hp (he thinks)

so I guess low 10's would be a goal

We need traps, tire height, and shift rpm, thats all. Turn corners and go straight = LSD. Not cheap.

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I have know idea about trap speed or anything else ive never drag raced before and I dont know much about it.

i probably wouldnt rev the engine over 8k and rear end gears wil be 4.35

26 inch tires

Well, I was asking all the info to caluclate a rear gear. 26 in tire, through the traps in 4th, at 127 mph (good for solid 10's) and a 8000 rpm rev limit/shift point says you need a 4.88 gear. A 4.35 gear will gear the car for 142 mph. Up to you.