[lolathemustang]

I've got a 68 mustang 289 (bored .040 over) and it has the stock 8 inch rear end in. This car is my daily driver but I would like to make it faster off the line. What kind of a gear ratio can be put in that would make me a lot jumpier but not kill the highway driving? I don't want to be whining down the freeway at 45 at 4500 rpm. Am I correct in assuming that I don't need the 9 inch rear end because I don't think I need one partly because the engine is not all that built and I don't have too much money. Also, where is the best place to get one of these gearings and what is a good price for the type of gearing I'm looking for? I don't want this ratio to adversely affect mileage or put too much strain on the engine. Please help, I don't know much about rear ends.
Thanks!

[bud-23]

I have a 67 with a built 302. I'm running a stock 8in with a 3:00 gear. 67 and 68 offered either a 3:00 or a 3:20. If you put in a 3:55 with 25 inch tires you will turn about 3400 rpm at 65 mph. I need the tall gears because its 50 miles east or west to town. I would't go any lower than the 3:55 if you want to drive on the BIG road. HTH. Norm.

[lolathemustang]

thank you for your help bud-23. do you know of a good resource for gears? does anyone else know of a good place to get them? junkyards? thanks

[bud-23]

I get mine from Border Motor Parts in Spring Valley (San Diego). Too far for you to drive. I always put in new gears but you can find the pumpkins in wrecking yards. A new set (ring,pinion,brgs,seals) runs about 275.00. HTH. Norm.

[lolathemustang]

Thanks so much for your help. I plan to put in the 3:20's or the 3:55's soon.

This was my first post and I thought it was great. This site is really cool and I look forward to posting more.
Thanks!

[bud-23]

There is plenty if help out here. From reading your first post you know how to ask the question and give the information about your problem. Doing so keeps us from reading between the lines. Norm.

[snkbyt]

Randy's Ring and pinion are in all the street rod magazines at the back. The are out of Seattle. They have all posi's too! You don't say what trans you're running but that has to do with the equation. I run 3:73 in all my cars but the have overdrive trans. 2500 @ 65mph. Only way to have the best of both worlds. If you have 3 speed A/T or a 4 speed think a 3:25 or close would work good.

Forgot to tell you that you need to know what you have now. Think the 8" has a rear cover. Count the teeth on the ring gear and the pinion. divide the pinion into ring and thats the ratio you have. Can also mark the drive shaft and an axle. Rotate the axlel one full turn while seeing how many turns the drive shaft went to get a real close idea of ratio. ie: 3 1/2 turns 3:50 ratio

[lolathemustang]

Thanks guys

Snkbyt, I have a C4 three speed. Will this be able to handle the 3:50 or would something around 3:25 be better for my purposes?

Thanks, Ben

[snkbyt]

The higher the ratio,3:55, the faster it comes away from the line and also will go into the next gear faster(lower road speed)also less tire slippage. The only negative is the top speed will be slower because of higher engine rpm. The lower the ratio this all reverses. If I was doing mainly city driving not extended 65mph I'd use the 3:55. For highway I'd be down in the low 3:00 or high 2:00 ratios. Also the speedo changes with ratios so you have to deal with that too. There are web sites that tell on speedo . Ray

[Onestreetrodder]

Originally Posted by lolathemustang

thank you for your help bud-23. do you know of a good resource for gears? does anyone else know of a good place to get them? junkyards? thanks

I just bought a 9" ring & penion from Summit Racing, for
$129.00 Same price from JEG'S. And it Works good.
ONESTREETRODDER.

[FEDDO]

the 8'' ford has a drop out chunk. no cover on the back.

[xntrik]

You probably have 2.80 gears now.

235.60x14 tires (25 inch diameter) and 3.25 gears will be about the best without overdrive.. about 2650 @ 60 mph.

67 and later Fairlanes, Mustangs, Granadas, Mavericks, Mustang II. Just have to snoop around to find the right ratio.

62-66 Fairlane cars were all 8" rears and had 3.25s with stick shifts, but the pumpkin housing is not as heavy duty as the 67 up... but probably would be OK in your situation, especially without a "posi" you will never hurt it.

You can probably pick up a complete 8" chunk ready to install for $ 35-50 at any junkyard.