what is the best gear ratio you can get in a 7 1/4 rear, and where can I find a set?

What do you mean by "best"?
Do you want high speed cruise and good MPG or do you want good "off the line" quickness and a low ET on a timeslip?

For a street car which sees a good amount of freeway driving, I use the 2.94 ratio.
DD

i wanted a good e.t.....but i don't know what gears will fit the 7.25 rear

here ya go baby, don't never say uncle wendell doesn't love you!
<BFG>

http://nationaldrivetrain.com/shopsite_ ... age15.html

Oh yeah, if you're planning blantant abuse it won't last long-- they tend to go **pop**

oof, and don't forget the special tool for "spreading the case"!

-JYH
64 Dart, 69 cuda, and a stack of busted 7.25's

You don't need the case spreader for the 7 1/4. It has bearing adjusters, with a hex in the center. Remove the axel, and use a bar with a large nut welded to the end. I use an old torsion bar. I am told there are some torsion bars that have a large enough hex, that can be used as is. A 7 1/4 rear with a suregrip, is a lot tougher then people think. I have run the 7 1/4 rear from 1974 till last year. It has many street miles and races behind a legal stock elimintor motor, to turbo and nitrous motors. I have two, one 3.91 ratio, and one 5.13. The car weight has been from 2500-3300 lbs. Have run a best of 13.4 at 97 on nitrous, 13.4 at 104 turbo, in the quarter. 8.16 at 84 in the 1/8 and 1.79 60 foot times. Didn't break it, but felt I was pushing my luck, so did change to 8 3/4.

_________________
Charrlie_S
65 Valiant 100 2dr post 170 turbo
66 Valiant Signet 170 nitrous
64 Valiant Signet
64 Valiant 4dr 170
64 Valiant 4dr 225

Very true, adding a SG unit certainly toughens up the beast; but finding them 7.25 SG units is one tuff proposition-- they seem about as common as hens teeth!
You know, i only grenaded one while doing a big nasty breakstand burnout. All the rest were while turning, mostly while applying light throttle. On the street no less!
Thanks for the tip on the 7.25, i was totally under the impression that you needed the case spreader thingy to get busy on it, but i haven't serviced one of those in years. I know that the 8.25 is the one that you can adjust with a t-bar. the C-body unit has the right legnth and hex, FWIW.

-JYH
64 Dart, 8.25 SG
69 Cuda, 8.75 SG
SoCal

thanx so much for the link, I knew somewher eout there you could get a good gear set for my rear end!
so, lets say I buy one of these things, anybody know a good step by step on installation?

Go look around at Randy's website, they have some good tech:
http://www.ring-pinion.com/tech/techind.html

Find a Factory service manual, that has all the step-by step info also.
DD