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I am wanting to put a limited slip rear end in my '68 coupe. I have a top loader 4 speed as the transmission. The rear end currently is stock. My door plate is missing and I really don't know what gear I am running. I believe it's a 8 inch rear end with a 2.90... I have been reading about the explorer rear swap. The ratio is 3.75... My father (also a mustang enthusiast) believes that will be too low for cruising on the highway... What are you running? I need some advice..
 

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Currently in my '69 I'm running a 3.00. This week I'm ordering a 3.40 center section with limited slip. At first I wanted 3.80 then 3.50 then 3.25 and have finally settled on the 3.40......I did all this for the same reason you are. I do drive highways and did not want the engine buzzing when on the freeway.

In the yellow '90 Fox below we have 3.73, but behind a 5-speed. It woeks well, but if you drop it down into 4th, it is not much fun to run 65. 3.73 or 3.80 in my opinion would be great for around town but would soon become a pain on the freeway behind a 4-speed.

I'm getting mine from one of the e-bay vendors, he runs "ford8and9inchrears.com".
Tom
 

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My 66 has 3.50 gears w/ 4 speed and is buzzing about 3500 at 70, very busy.
 

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I'm currently using a 3.00:1 traction lock with a four speed. I do a lot of highway driving, but if I didn't have a Paxton installed I would've gone with a 3.25:1


Z.
 

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Close or wide ratio? If you have a close ratio then you need 3.50 at a minimum. If wide ratio then 3.25 is a good gear. 2.79 rear is no good for any manual transmission - especially behind a small block. Too much trouble launching it.
 

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Close or wide ratio? If you have a close ratio then you need 3.50 at a minimum. If wide ratio then 3.25 is a good gear. 2.79 rear is no good for any manual transmission - especially behind a small block. Too much trouble launching it.
if you have a toploader you can get a 2.90 1st gear to avoid the launch issue (I did).

First Gear

Z.
 

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I had 3.70's in my 66 with a CR toploader. It wasn't bad cruising at highway speeds, but did burn the fuel. Now I'm running 4.11's and well...it burns more fuel, but it will make your eyes pop out the back of yer head under WOT.
 

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I'm also running a 4:11 in my fastback. The engine just screams at highway speeds. I'm considering swapping it for a 3:73 or maybe even something close to 3:50.
 

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I have a stock 289 with a wide-ratio T10. I have a peg leg 8" and am using 3.25 gears. It was a good compromise for me.
 

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HAHA I win I have a 4:56 with a full spool. DUH dumb move.
I traded my Pete Jackson gear drive for it back when I wanted to drag race all the time when I was 18. Now I would love to trade it for a nice 3.50-3.73 but they are few and far between in Central IL
 

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I am running a 3.25 9" with my Toploader.
 

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To give you a better idea of the gear change....for every .25 gear ratio change, the rpm's will change by 300.
 

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I'm running 3.0 gears (stock) in my 9", CR (according to the tag) 4-speed

I think it's spinning too fast at 70. I would love an overdrive gear.
 

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What is a good compromise? I will eventually have a 4 speed wide ratio toploader between a 408W and a 9 inch rear. I will be driving on country roads, but some of them are long, so it would be like driving on the highway.
with a 408 ci you have plenty of torque. In your shoes I would go with a 3.00:1



I'm running 3.0 gears (stock) in my 9", CR (according to the tag) 4-speed

I think it's spinning too fast at 70. I would love an overdrive gear.
do you have a tach? I've got a 3.00:1 gearing and a tire diameter of 24.7 (195/70-14).

at:
60 mph the rpm is: 2450
70 mph the rpm is: 2858
75 mph the rpm is: 3062
80 mph the rpm is: 3266
85 mph the rpm is: 3470
90 mph the rpm is: 3715

I've done long trips at 85 mph for hours at a time (west Texas & New Mexico). The rpm at that speed seemed OK to me.

Z.
 

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My car has a 3.00 and it cruises down the highway like a sewing machine. I had a 3.50 in my first fastback and I always felt I was looking for "5th gear" when I was on the highway - it was just a bit too high.
I'd like to up it to a 3.25 but it's just not worth the $600-700 for new gears installed in it when I have something that's pretty good with my 3.00.
If you want a stop light to stop light car go start at 3.50 or higher. If you want a highway cruiser 3.00 is pretty good.

I'd like to hear what someone with a 3.25 thinks how their car drives.
 

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always depends on what you want to compromise

Me, I compromised on first gear launch, with 3.50 and close ratio TL, I have a tall first gear but mid first gear and on - my car is an absolute scream to drive.

I don't drag race and I don't need to spin tires so for autocross and a little track time plus street sport its a great combo. Now; over 60 mph with my loud pipes well, life sucks after 30 minutes. I am going to try 3.00 like the people above me. I will compromise in first gear launch and my 351 has the torque to pull taller gears. I won't compromise on sound, whats a good midlife crisis without a rumble...

I am in a similar issue with 65gt, I don't want to go up to 3.25 for the cost thinking I need to go all the way to 3.25.

Anyone wanting to part with their 9" 3.00s can PM me, especially if there is a pumpkin and great pricing involved.

Cheers,

M
 

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I'm running a 9 inch with Richmond 3:70 gears with a 302 Mexican block thats built along the lines of a 289 hipo. With a little more hipo to it and yes it really gets busy goin down the highway at 70 but it sure is fun.
 
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