T5 Five speed slant six 74 Dart Sport.

RustyRatRod said
....and I bet that thing would have gotten much better mileage with a 3.55 or even a 3.91 and no matter what you do, you cannot make some folks understand that. Are you listening, @greymouser7 ? Some folks think the lower numerically you go with gear ratio, the better mileage you get and that's just not true at all. If you get an engine so far out of its optimal operating range, you ruin any chance of good economy, not to mention decent power. With that 2.76 gear, I bet you were downshifting with the slightest head wind. That had to SUCK.

That is what killed the 700R4 in one of my S10s. .7 Overdrive, 3.08 gears with a 26" tall tire. I couldn't drive around town in OD. Would barely tip in just to accelerate and it would shift out of it; sometimes down to 2nd if I leaned in too far. Only turned 2000rpm to do 70mph. Wore itself out constantly shifting up and down. That trans lasted 50k miles. My dad's 1994 Chevy 1500 on the other hand has 27.5" tall tires, a 4.10 gear, the same .7 OD, and is turning 2500rpm to do 70. I replaced the transmission at 350k miles. Replaced the engine at 798k miles, and then the transmission again at 900k. That big truck with a 4.3l V6 gets 25mpg on the highway. High gears are fine for a three speed or non-od four speed, but not for an od trans. Hell, I had an 80s Monte Carlo with a 2.19 gear and a three speed auto.