[Formulajones]

Originally Posted by scott70

Most of my " normal" driving is around town,55 mph and 65 mph. The 2.87 first gear is appealing to me as much as having the overdrive. I will admit I'm not much of a putt putt. The car has its original drivetrain but I put it through its paces. Have been since 1986.

You'll enjoy the increase in first gear. Much more pleasurable to drive around town. That's the benefit of these overdrives. Not only getting a comfy cruising rpm but you also help out the other end of the spectrum at the same time. You get the best of both.

55-65 won't be a problem with your setup in 5th gear with the .68 but if you really don't want to putt-putt then just don't use it at lower speeds if you'd rather hear the engine spinning.

Me personally, 65 mph with this deal is 1800 rpm (3.31/.68/27" tire), I wouldn't consider that putt-putt, that's just nice comfy cruising, no engine noise, and should return exceptional mileage too. Once you get used to the idea of having a muscle car that actually cruises like a new car in overdrive you'll find yourself using it more and more.

It's hard for people to get used to that idea after decades of driving them without an overdrive, they either feel the engine still needs to be spinning higher rpm or they just have an engine that requires some more fine tuning to make it happier at those lower cruise speeds.

You can look at it this way, how slow do you go in 4th gear putting around before you think you need to drop down to 3rd gear? At what rpm do you bring the engine down to before you feel like it's struggling? Well 5th gear will act the same way.

From my experience driving 4 speeds for decades, a typical well tuned muscle car can drive around in 4th gear in 25-35 zones no problem at very low rpm.
Your setup with 3.31's and a 27" tire does 35 mph at 1500 rpm. That should not be an issue at all. Or maybe you like just leaving it in 3rd gear?? The overdrive just gives you another option