The older automatics had 3.0:1 first gears. My 2011 Chevy has a 6.0:1 first gear and 4th gear is still under driven instead of a 1.0:1 high gear.
The "granny" gear in the 4-speed in my '79 F-250 was 6.69:1.
5th is barely an overdrive, 6th gear is 0.67:1.
My pickup has 3:73 gears and with the transmission gearing I wouldn't care to have any lower gears in the differentials.
Besides the gearing the newer engines have way more power than the older trucks with 3&4 speed trans.
At 87 mph I'm still under 2500 RPM and that works good for me.