Join Date: Jun 2011
Location: Colorado Springs
Do you drive your Mustang a lot? If you do, then I do think it's worthwhile to install an overdrive.
If you don't drive your Mustang a lot, then no. It's not really worth it.
I spent a lot of money, time and effort installing a TKO-600 in my Mustang. I wondered if it was worthwhile. Last I week I drove the car to Steamboat Springs for the Mustang roundup; about 5 hours each way. Oh, good golly, it was so worth it! I have a 3.70 rear gear. In overdrive, I can breathe on the gas pedal and the car does 70 MPH. As long as I keep the RPMs at or above 2,000, the car will effortlessly cruise; even up steep inclines like I-70 through Vail Pass.
On the way to Steamboat, I stopped in Silverthorne, which is about half way, to gas up. The car took 9 gallons. I got to Steamboat and still had half a tank. Thus, I could have made the whole trip on one tank of gas (22 gallon tank). Yeah, I know. A lot of people say, "Who cares about MPG?". But again, if you drive your Mustang a lot, it does matter. It's no fun spending $50 or more to fill the tank, but it downright sucks when you have to do it constantly. An overdrive also significantly reduces wear on the engine.
Now, whether or not a T-5 is the best option may be debatable. If it's in your budget, a TKO would be better. You'd have a lot more room for future engine mods. Although, many people have put many miles on a T-5 with pretty potent engines. Your car, your choice.
FYI, if you're thinking you can find a good, mid-90s T-5 at a local salvage yard and bolt it in, think again. You might get lucky, but pretty much any used T-5 you find it going to be completely shot. If you can rebuild it yourself, cool. By the time you pay someone to rebuild it, you might as well buy a new T-5. You will need an adapter/spacer and a new trans cross member. You might have to shorten the drive shaft. You can use the factory, Z-bar clutch linkage. That's what I did and I'm perfectly happy with it. (I did install a rollerized clutch linkage.)
That's my take anyway.
Last edited by Klutch; 06-24-2019 at 11:03 PM.