A glide from behind a v-8 is a bit better if you are not going to freshen the trany.
You can determine the gear ratio of the planetary by measuring the diameter of the splined section that sticks out of the tail housing. A vernier caliper will work
there is a slight difference in diameter size from the 1.82 & the 1.76 gear ratios.
Dont worry how old you are... it is the mileage on your body that adds up.