Rear ends - explaination

Here's a quick tutorial.

8 3/4 refers to the size of the ring gear. Bigger is stronger, but takes more power to turn due to inertia and frictional losses. You won't need a 8 3/4 rear with your slant 6.

Gear ratios are stated like the following: 2.73, 3.23, 3.55, 3.73 etc. The ratio is how many turns the driveshaft must make to turn the axels once. Higher (numerical) gears will increase acceleration and pulling power but limit your top end speed.

Lower (numerical) gears will in most cases increase your highway gas mileage and theoretical top speed.

Hope this helps.