w00w00 said:
that seems like a huge difference in final gearing. mainly cause the 2.41 seems really small. is that due to the inefficiency of the original engines? they deliver less torque so you go with a smaller final drive gear? love learning about the classics from you danny.
Well actually the taller gears (numerically lower, i.e.2.41:1) gears weren't used so much as a means to combat low torque, since this could be accomplished through transmission gearing. At the time, common transmissions were 2 and 3 speed automatics, or 3 and 4 speed manuals and all had a final drive of 1.1:1. The higher (taller) gears were used mainly to lower engine RPM at highway speeds increasing gas mileage and at the same time increasing engine life. Back in those days a car with 80k was considered used up and most were pretty well worn out and tired. But the lower gears (numerically higher) are always preferred from a performance (1/4 mile) point of view because it make the car quicker (not faster).
Then came along the OD tranny's in both auto and manual tranny's reducing the final drive to something less than 1.1:1 which also served to accomplish the same end as does the taller gearing in the diff.
As the industry progressed so did transmission technology, the manuals became 5 and 6 speeds and the automatics became 4 and 5 speeds with torque converters locking up making them slip less and much more efficient. With all these transmissions geared to lower engine RPM in the final drive, and engines becoming smaller with much less torque (but more fuel efficient), most cars became a lot less fun to drive and were very sluggish. But as people demanded fun / sporty cars the differential gears started to become numerically higher (lower) to give these cars more launch power and a whole lot more fun to drive. And since the tranny's have improved so much, going to a lower final drive with 4/5/6 speeds OD transmissions allowed a great compromise between fuel efficiency, engine wear, and low end punch.
