T5 Five speed slant six 74 Dart Sport.
Anyone that reads the ratios knows that the 833 OD is not a performance transmission
Again absolutely true
When shopping for transmission for my combo, I found out a few things;
The 2.47 low 4-gear was not gonna work at all.
the 2.66 was not much better. I needed more on the bottom and less on the top.
So I started throwin all the chunks I had at the 2.66, until I found a First gear that I really liked,
Then I threw other chunks at it until I found what the engine liked to cruise at.
Then I calculated the ratio spread I needed, or hoped for.
What I found was that the engine liked to cruise at not much less than 2200, and I liked a starter gear of about 10/1.
To cruise at ~2200 requires a final drive gear of about 2.76
So the total spread was from 10.0 to 2.76 which is
10/2.76=
3.62.
To run the 2.66 box to get a 10/1 starter requires a 3.76gear, rounds to 3.73s. so the spread is (2.66 x 3.73)/3.73=
2.66 so obviously at only 73% of what I need, that will never work.
And; to run the 3.09 overdrive at 10/1 requires a 3.23 rear gear, which makes top gear 3.23 x .73 =2.36, so the spread is
(3.09 x 3.23)/2.36=
4.23 which is 16.8% too big
So I latched on to the '78 GVod. with the 2.66 box, to get 10/1 starter requires 3.73s again, making overdrive into 2.91s
So the spread is (2.66x 3.73)/2.91 =
3.57, daym that's close so I bought one installed it and loved it.
For the keckuvit, I installed a 3.09low, Command box and 3.55s
This made the starter 10.97, and the cruiser 2.77, and the spread is now, 10.97/2.77=
3.96 which is even more fun. That was around 2004, and there's no going back cuz I sold everything bigger than 3.55s, except a set of 4.88s.
I ran this box with 3.23s and a smaller torquier cam and she loved it. The starter was 9.98 and the cruiser was 3.52, so the spread was
9.98/2.52= still
3.96 of course, but 65= 2040
For chits and giggles I installed that GVod behind my 833od for like a year or two, with various gears, and ended up with 3.55s. That made a starter of 10.97 and a double overdrive of 1.97, a spread of
10.97/1.97=5.57 This made 65= 1600 annnnnd the small-cammed 367 pulled it!
I highly recommend to all you gear-bangers to just once in your life do this with a Thermoquad , and floor it from 55 mph with the windows up so you can hear that mighty 850 roar, and roar, and roarsumore ............................ , cuz you'll run out of power long before you run outta revs, lol. By the math, 120mph is still only 3000rpm.
I ended up running that combo with 4.30s, for the sweet parade gear of 3.5mph=580 rpm.