T-5 in 57 Ranchero ---Which Rearend Ratio.

[kens65fb]

I just picked up a very nice  World Class T-5 trans for my Ranchero project.
The trans has the 3.35 first gear, as do most t-5 transmissions.
I checked out the rear-end presently in my car,  and the tag reads 3.70
How will this combo work?? ---Will I need to go to a different ratio ?
This vehicle will see no track time, but I am an aggressive street driver.
Thanks

[shopratwoody]

Sounds like a good ratio to me. Should work good.

[Frankenstein57]

That is my choice with a 351 W, and a t-5.  You may want to read recent posts on trans swaps, ect. If you have the stock bench seat, you won't clear the shifter with a mustang trans. I ran into tunnel clearance problems too. good luck, Mark

[57AGIN]

Kens65fb:

The 351W, with a 3:70 rear end gear is a great combo.  I just wish I had the overdrive gear you have in your T-5 in my T-10 to get my 57 (with a T10) around using a lot less gas on the freeway trips to shows, etc.  That trans & rear end ratio in first gear is like mine would be if I had a set of 4:30's in the rear.  A very strong combo off the line, with good pull through the lower gears.

Bob
57AGIN

[57Cust300]

I have just installed a T5 with a 3:70 gear. With the 3.35 first gear 1st gear is almost useless.
My plan is to go to a 2.95 1st and to a 3.55 rear. If you are into drag racing, go with the 3.70
but IMHO the 3.70 is a bit much on the street (especially 1st gear).

[57AGIN]

57Cust300:

Yes, you are correct the T-5 with a 3.35 1st gear coupled with a 3.70 rear gear is the same as having a close ratio T-10 with a 2.20 close ratio 1st gear coupled to a 5.63 rear gear.  From my racing days this would even be pretty steep even for a high revving drag car.  However a T-5 having a 2.93 1st coupled to a 3.5 would be a good combination.  As I also recall from my days crawling under parts cars in ghe mid-60's, 3.5 rear gears aren't too hard to find if you don't want to invest in new ones.

Bob
57 AGIN

[KidKourier]

   Does anybody remember the formulas for figuring out the rearend ratio = engine rpm at 65mph x final trans gear devided by tire height and also the engine rpm you'll be turning at 65 mph to keep it in its sweet spot(not lugging or over revving) something like trans final gear X tire heigth X rearend ratio???Would like to try figuring these out before installing my T-5 with 3:35 1st gear--- maybe higher rear gears/tire height?Got such a good deal on the T-5,hate to sell it but want to enjoy driving my car so maybe going with the T-5Z trans is the better deal?       Skip -Kid Kourier

[canadian_ranchero]

   Does anybody remember the formulas for figuring out the rearend ratio = engine rpm at 65mph x final trans gear devided by tire height and also the engine rpm you'll be turning at 65 mph to keep it in its sweet spot(not lugging or over revving) something like trans final gear X tire heigth X rearend ratio???Would like to try figuring these out before installing my T-5 with 3:35 1st gear--- maybe higher rear gears/tire height?Got such a good deal on the T-5,hate to sell it but want to enjoy driving my car so maybe going with the T-5Z trans is the better deal?       Skip -Kid Kourier

here are some that i have.tire revolutions per mile. divide the loaded radius in inches into 10084.the other one i have is speed in the gears,engine rpmx60 divided by gear ratioxtire rpm=mph. hope this helps

[KidKourier]

       Thank you,new there was a formula but just couldn't  remember all of it!  KID

[Ford Blue blood]

I built a 66 Falcon Ranchero with a fuel injected 302 (speed density) and T-5.  The car had a 3:23 and it was perfect for the set up.  Car got a little over 30 MPG and had great drivability.

[suede57ford]

The low first and 3:70's in the rear will work perfect with a 27-28 tall rear tire.

The low first really helps out the street driving, especially with a small cubic inch engine like a y-block or windsor.

Your combo will just turn 2000 rpm at 70mph.

Run what you got as you nailed it with the right combo.

Pat

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